JP6505630B2 - Direction control valve - Google Patents

Description

  The present invention relates to, for example, a direction control valve which is mounted on a construction machine such as a hydraulic shovel, a wheel loader and the like, and is suitably used to drive and control a hydraulic actuator such as a hydraulic cylinder and a hydraulic motor.

  Generally, in construction machines such as hydraulic shovels, direction control is performed between a hydraulic actuator and a hydraulic source in order to supply and discharge pressure oil from a hydraulic source such as a hydraulic pump to a hydraulic actuator (for example, hydraulic motor, hydraulic cylinder etc) A valve (spool valve) is provided. In this case, a plurality of directional control valves are provided in accordance with the number of hydraulic actuators, and the plurality of directional control valves constitute a control valve device composed of an assembly of these.

  Here, during operation of the direction control valve (that is, when pressure oil from the hydraulic pump is being supplied to the hydraulic actuator), the pressure on the hydraulic actuator side is the hydraulic pump according to fluctuations in load applied to the hydraulic actuator. May be higher than the pressure on the side. At this time, a check valve is provided between the hydraulic pump and the direction control valve to shut off the flow of pressurized oil from the hydraulic actuator to the hydraulic pump so that the hydraulic fluid does not reversely flow from the hydraulic actuator to the hydraulic pump. ing.

  On the other hand, Patent Document 1 describes a configuration in which a plurality of directional control valves are provided for each hydraulic actuator in order to control a plurality of hydraulic actuators. Specifically, in Patent Document 1, a directional control valve for a boom that controls a boom cylinder, a directional control valve for an arm that controls an arm cylinder, a directional control valve for a bucket that controls a bucket cylinder, and a swing hydraulic motor In addition to standard directional control valves, such as directional directional control valves for turning, left and right directional directional control valves for running left and right traveling hydraulic motors, spare directional control for controlling the hydraulic actuators of the attachment An arrangement with a valve is described.

  By the way, the attachment (working tool) of the hydraulic shovel may be changed, for example, from the bucket used until now to another type of attachment such as a crusher, a breaker, a cutter, or a crusher. At this time, for example, in order to secure the flow rate of the pressure oil to the hydraulic actuator of the attachment, at the maintenance plant of the hydraulic shovel or the like, along with the replacement of the attachment, an additional hydraulic pump in addition to the existing hydraulic pump already attached. (External pump) may be retrofitted (add-on). That is, an additional hydraulic pump is attached to a pump mounting portion (power transmission mechanism) of the engine, and the additional hydraulic pump and a direction control valve (for example, spare direction control valve) are connected by an additional external pipeline. Therefore, additional hydraulic pumps may be modified (remodeled) to supply pressure oil through additional external pipelines.

  In this case, for example, as described in FIGS. 2 and 3 of Patent Document 2, the back pressure chamber side of the check valve for the existing hydraulic pump provided in the valve casing of the direction control valve, It can be an external input port that can be connected to an external conduit. That is, an additional external pipeline can be connected to the external input port, and pressure oil can be supplied from the external pipeline to the spool side of the directional control valve through the external input port.

JP, 2013-199977, A Japanese Patent Application Laid-Open No. 58-113604 (Japanese Patent Publication No. 01-54588)

  Consider a configuration in which pressurized oil is supplied to the hydraulic actuator from the additional hydraulic pump through the additional external pipeline, the external input port, and the directional control valve as described above. In this case, a check valve that shuts off the flow of pressure oil from the hydraulic actuator to the additional hydraulic pump so that the pressure oil does not flow back to the additional hydraulic pump even if the pressure on the hydraulic actuator side increases It is necessary to provide a check valve for the hydraulic pump of

  Here, it is conceivable to provide an additional check valve for the hydraulic pump, for example, in the middle of the external pipeline. However, in this case, two lines between the additional hydraulic pump and the external input port, that is, a line connecting the additional hydraulic pump and the check valve, and the check valve and the external input port It is necessary to have a pipeline connecting the

  On the other hand, it is conceivable, for example, to incorporate a check valve for the additional hydraulic pump in the valve housing (block) of the directional control valve. More specifically, it is conceivable to incorporate an off-the-shelf (general-purpose) check valve (check valve assembly) into the valve casing. In this case, one additional pipeline can be connected between the additional hydraulic pump and the external input port.

  However, in this case, in order to be able to incorporate the external input port and the already manufactured check valve in the valve casing, for example, it is necessary to process the existing valve casing. That is, in order to be able to incorporate the external input port and the already manufactured check valve, processing for enlarging the passage of the existing valve casing is required. In addition to this, in order to reduce pressure loss, it is necessary to enlarge the passage of the existing valve casing. As a result, it is necessary to perform processing for changing the hole shape of the existing valve casing or separately prepare a dedicated valve casing.

  Here, when processing the existing valve casing, work for removing the direction control valve from the hydraulic shovel (removal work of hydraulic line such as hydraulic hose, removal work of the direction control valve), processing the valve casing Work (disassembly work of direction control valve, processing work of valve casing, work of assembling direction control valve), work for attaching direction control valve to hydraulic excavator (work of mounting direction control valve, hydraulic hose such as hydraulic hose) Installation work etc. is required. In the case of separately preparing a dedicated valve casing, almost the same operation is required except for the operation of newly manufacturing the dedicated valve casing. In either case, since the work is bothersome and time-consuming, the time during which the hydraulic shovel can not be operated will be long.

  It is an object of the present invention to provide a directional control valve which can incorporate check valves for other hydraulic sources (additional hydraulic pumps) in the existing valve casing.

  The direction control valve according to the present invention comprises a valve casing provided with a spool sliding hole, and a pair of hydraulic pressure source side oil passages spaced apart in the axial direction of the spool sliding hole and provided in the valve casing. And a pair of actuator ports provided in the valve casing so as to be separated in the axial direction of the spool sliding hole with the pair of hydraulic pressure source side oil passages interposed therebetween, and slide in the spool sliding hole. A spool which is movably inserted to connect and shut off the pair of hydraulic pressure source side oil passages and the pair of actuator ports, respectively, and pressure oil is provided to the valve casing from one hydraulic pressure source. Provided on the valve casing opposite to the one side connection port, the one side connection port connecting the one side supply passage to be supplied, the pair of hydraulic pressure source side oil passages and the one side supply passage, and the one side connection port The other side connection port that opens to the outer surface of the casing, and the other side Is connected to a connection port comprising a other side supply passage pressure oil from another other hydraulic source is supplied to the hydraulic power source of the one.

In order to solve the problems described above, the feature of the configuration adopted by the present invention is a valve provided with one side in the one side connection port and blocking the flow from the pair of hydraulic pressure source side oil passages to the one side supply passage. A flow path blocking member which is a body and the other side is inserted into the other side connection port to form a sleeve, a valve seat member provided on the other side connection port and restricting the position of the flow path blocking member, and The valve seat member is provided so as to be able to be separated from and seated on the valve seat member to allow the flow from the other side supply passage to the pair of hydraulic pressure source side oil passages and block the flow from the pair of hydraulic pressure source side oil passages to the other side supply passage A check valve, and a sleeve opening provided in the sleeve of the flow passage blocking member and constantly communicating between the inner surface and the outer surface of the sleeve, and the valve body of the flow passage blocking member includes the pair From the hydraulic source side oil passage to the one side supply passage Blocking the flow constantly and in that the from one side supply passage has a configuration you blocking always flow to the pair of hydraulic source side oil passage.

  The directional control valve of the present invention can incorporate check valves for other hydraulic pressure sources in the existing valve casing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the hydraulic shovel by which the direction control valve by 1st Embodiment was mounted. It is a hydraulic circuit diagram showing a drive circuit of a hydraulic shovel when attachment is a bucket. FIG. 6 is a hydraulic circuit diagram showing a drive circuit of a hydraulic shovel when an attachment is changed from a bucket to a crusher and an additional hydraulic pump is attached. It is a longitudinal cross-sectional view which shows a 1st direction control valve. It is a longitudinal cross-sectional view which shows a 2nd direction control valve. It is an expanded sectional view of the (VI) part in FIG. 5 which shows a flow-path blocking member, a valve seat member, a check valve etc. FIG. 7 is a cross-sectional view of the flow path blocking member, the check valve, and the like as viewed in the direction of VII-VII in FIG. It is a perspective view which shows the flow-path interruption | blocking member in FIG. It is sectional drawing which looked at the flow-path block member by 2nd Embodiment, a check valve etc. from the same direction as FIG. It is a perspective view which shows the flow-path interruption | blocking member in FIG. It is sectional drawing which looked at the flow-path interruption | blocking member by 3rd Embodiment, a valve seat member, a check valve etc. from the same direction as FIG. It is sectional drawing which looked at the flow-path interruption | blocking member by 4th Embodiment, a valve seat member, a check valve etc. from the same direction as FIG.

The present invention belongs to an invention group including a plurality of inventions described below, and hereinafter, first to fourth embodiments will be described as embodiments of the invention group. Among them, the first to third embodiments correspond to the invention described in the claims.
Hereinafter, a direction control valve according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the direction control valve constituting a control valve device of a hydraulic shovel is applied.

  1 to 8 show a first embodiment. In FIG. 1, a hydraulic shovel 1 as a representative example of a construction machine (working machine, working vehicle) includes a self-propelled crawler type lower traveling body 2 and an upper portion rotatably mounted on the lower traveling body 2 It is configured to include the swing body 3 and a working device 4 also called a front device provided on the front side of the upper swing body 3 so as to be able to move up and down. The lower traveling body 2 and the upper revolving superstructure 3 constitute a vehicle body of the hydraulic shovel 1.

  The lower traveling body 2 includes, for example, a crawler belt 2A, and left and right traveling hydraulic motors for causing the hydraulic shovel 1 to travel by driving the crawler belt 2A in a circulating manner. On the other hand, the working device 4 includes, for example, a boom 4A, an arm 4B, a bucket 4C as an attachment (working tool), a boom cylinder 4D for driving these, an arm cylinder 4E, and a working tool cylinder 4F. . In this case, the boom cylinder 4 </ b> D pivots the boom 4 </ b> A with respect to the upper swing body 3. The arm cylinder 4E rotates the arm 4B with respect to the boom 4A. The work implement cylinder 4F rotates the bucket 4C relative to the arm 4B.

  In addition, FIG. 1 has shown the hydraulic shovel 1 of the attachment of the working apparatus 4 of the bucket 4C. That is, FIG. 1 shows, for example, the hydraulic shovel 1 at the time of factory shipment to which a bucket 4C is attached as an attachment of the work device 4. Moreover, FIG. 2 has shown the hydraulic circuit of the hydraulic shovel 1 when an attachment is the bucket 4C. On the other hand, FIG. 3 shows a hydraulic circuit when the attachment of the working device 4 is changed (replaced) from the bucket 4C to another attachment, for example, a crusher 4G.

  That is, for example, in addition to changing the attachment from the bucket 4C to the crusher 4G in a maintenance factory etc., in addition to the hydraulic pumps 9A and 9B installed from the time of factory shipment, an additional hydraulic pump 10 is retrofitted ( When attached with an add-on). In this case, the crusher 4G is provided with, for example, a work tool drive cylinder 4H that is a hydraulic actuator of the attachment. The work implement drive cylinder 4H drives (opens and closes) the crusher 4G.

  Boom cylinder 4D consisting of hydraulic cylinders, arm cylinder 4E, work implement cylinder 4F, work implement drive cylinder 4H, left and right traveling hydraulic motors consisting of hydraulic motors, turning hydraulic motor 5 described later (see FIGS. 2 and 3) Become hydraulic actuators (hydraulic devices, hydraulic devices) that are driven (actuated) based on the supply of pressure oil, respectively. In FIG. 2 and FIG. 3, the left and right traveling hydraulic motors are omitted in order to avoid the drawings becoming complicated.

  The upper swing body 3 is added to a swing hydraulic motor 5 (see FIGS. 2 and 3) for swing driving the upper swing body 3 with respect to the lower traveling body 2 and a counterweight 6 for balancing weight with the work device 4; A cab 7, an engine 8, hydraulic pumps 9A, 9B, an additional hydraulic pump 10 mounted as needed, and a control valve device 21 are included.

  The cab 7 defines a cab and is provided on the front left side of the upper swing body 3. In the cab 7, a driver's seat where an operator is seated is provided. Further, around the driver's seat, there are provided an operating lever / pedal device for traveling operated by the operator and an operating lever device for operation. The control lever / pedal device and the operation control lever device for work output a pilot signal (pilot pressure) corresponding to the operation of the operator to the control valve device 21.

  The engine 8 is disposed on the front side of the counterweight 6 in a state of being placed horizontally. The engine 8 is configured by an internal combustion engine such as, for example, a diesel engine. The engine 8 serves as a drive source (motor) of hydraulic pumps 9A and 9B described later and an additional hydraulic pump 10. The drive source can be configured by, for example, an electric motor or an internal combustion machine and an electric motor other than the internal combustion engine.

  As shown in FIG. 2, standard hydraulic pumps 9A and 9B (hereinafter simply referred to as hydraulic pumps 9A and 9B) are attached to one side of the engine 8 in the left and right directions. Further, as shown in FIG. 3, an additional hydraulic pump 10 is attached to one side of the engine 8 in addition to the hydraulic pumps 9A and 9B. Here, the hydraulic pumps 9A and 9B shown in FIGS. 2 and 3 correspond to, for example, existing hydraulic pumps that have been installed from the factory. That is, in the hydraulic pump 9A, 9B, for example, at the manufacturing plant of the hydraulic shovel 1, the attachment of the working device 4 is mounted on the hydraulic shovel 1 of the bucket 4C as a standard. On the other hand, the additional hydraulic pump 10 shown in FIG. 3 is, for example, maintenance when the attachment of the working device 4 is changed from the bucket 4C to the crusher 4G, and becomes a factory different from the factory for It will be installed later in the factory. That is, the additional hydraulic pump 10 corresponds to a retrofit hydraulic pump.

  The hydraulic pumps 9A, 9B and the additional hydraulic pump 10 are driven by the engine 8. The hydraulic pumps 9A, 9B, together with the hydraulic oil tank 13, constitute one hydraulic pressure source. In this case, the discharge side of the hydraulic pump 9A is connected to the hydraulic oil tank 13 via the center bypass pipeline 11A. The discharge side of the hydraulic pump 9B is connected to the hydraulic oil tank 13 via the center bypass pipeline 11B. On the other hand, as shown in FIG. 3, the additional hydraulic pump 10 constitutes, together with the hydraulic oil tank 13, another hydraulic pressure source which is a hydraulic pressure source different from one hydraulic pressure source. The discharge side of the additional hydraulic pump 10 is connected to a spare directional control valve 26 described later via an additional pipe line 12 serving as an external pipe line.

  The hydraulic pumps 9A, 9B and the additional hydraulic pump 10 are provided with various hydraulic actuators (left and right traveling hydraulic motors, cylinders 4D, 4E, 4F, 4H, turning hydraulic motor 5 etc.) mounted on the hydraulic shovel 1. It becomes a power source for driving. The hydraulic pumps 9A and 9B and the additional hydraulic pump 10 pressurize the hydraulic oil in the hydraulic oil tank 13 and discharge it toward the control valve device 21.

  The control valve device 21 is a control valve unit formed of an assembly of a plurality of directional control valves 22, 23, 24, 25, 26. The control valve device 21 includes various hydraulic actuators from the hydraulic pumps 9A and 9B and the additional hydraulic pump 10 in accordance with the operation of the travel control lever / pedal device and the operation control lever device disposed in the cab 7. The direction of the pressure oil supplied to 4D, 4E, 4F, 4H, 5 is controlled. Thus, the hydraulic actuators 4D, 4E, 4F, 4H, 5 are driven by the pressure oil supplied from the hydraulic pumps 9A, 9B and the additional hydraulic pump 10.

  Here, the control valve device 21 includes the boom direction control valve 22, the arm direction control valve 23, the work tool direction control valve 24, the turning direction control valve 25, and the spare direction control valve 26. It is comprised including. The boom directional control valve 22, arm directional control valve 23, tool directional control valve 24, turning directional control valve 25, and spare directional control valve 26 are hydraulic pilot directional control valves with 6 ports and 3 positions, respectively. It is composed of 2 and 3 omit the left and right traveling direction control valves as well as the left and right traveling hydraulic motors.

  The boom direction control valve 22 is provided, for example, between the hydraulic pump 9B and the boom cylinder 4D in the middle of the center bypass pipeline 11B. The boom direction control valve 22 controls the supply and discharge of pressure oil to the boom cylinder 4D. The arm direction control valve 23 is provided, for example, between the hydraulic pump 9A and the arm cylinder 4E in the middle of the center bypass pipeline 11A. The arm direction control valve 23 controls supply and discharge of pressure oil to the arm cylinder 4E.

  The work implement directional control valve 24 is provided, for example, between the hydraulic pump 9A and the work implement cylinder 4F in the middle of the center bypass pipeline 11A. The work direction control valve 24 controls the supply and discharge of pressure oil to the work cylinder 4F. The turning direction control valve 25 is provided, for example, between the hydraulic pump 9B and the turning hydraulic motor 5 in the middle of the center bypass pipeline 11B. The turning directional control valve 25 controls supply and discharge of pressure oil to the turning hydraulic motor 5.

  The boom direction control valve 22, the arm direction control valve 23, the work tool direction control valve 24, and the turning direction control valve 25 switch the pressure oil of the hydraulic pumps 9A and 9B which are one hydraulic source. It is a directional control valve to control, that is, a directional control valve for one hydraulic pressure source. The boom direction control valve 22, the arm direction control valve 23, the work tool direction control valve 24, and the turning direction control valve 25 correspond to the first direction control valve 31 shown in FIG.

  On the other hand, the backup directional control valve 26 is provided in the middle of the center bypass pipeline 11A. As shown in FIG. 2, when the attachment is a bucket 4 </ b> C, for example, the backup directional control valve 26 is not connected to any hydraulic actuator. A hydraulic actuator (not shown) may be connected to the backup directional control valve 26. That is, the pressure oil from the hydraulic pump 9A may be supplied to a hydraulic actuator (not shown) via the backup directional control valve 26. In these cases, that is, when the hydraulic actuator is not connected to the backup directional control valve 26, and when the backup directional control valve 26 is used as a directional control valve for the hydraulic pump 9A, the backup directional control valve 26 For example, it corresponds to the first direction control valve 31 shown in FIG.

  On the other hand, as shown in FIG. 3, when the attachment is the crusher 4G, the backup directional control valve 26 controls the supply and discharge of pressure oil to the work implement drive cylinder 4H of the crusher 4G. That is, when the attachment is changed from the bucket 4C to the crusher 4G and the additional hydraulic pump 10 is retrofitted, the spare directional control valve 26 is connected to the work tool drive cylinder 4H of the crusher 4G. At the same time, the backup directional control valve 26 is connected to the additional hydraulic pump 10 via the additional line 12. At this time, the spare directional control valve 26 is changed (remodeled) from the first directional control valve 31 shown in FIG. 4 to the second directional control valve 51 shown in FIG. Specifically, as described later, the lid 39, the check valve 41 and the biasing member 42 are removed from the first direction control valve 31 of FIG. 4 and the lid 59 and the flow path blocking member 61 of FIG. By attaching the valve seat member 64, the check valve 65 and the biasing member 66, the first direction control valve 31 of FIG. 4 is changed to the second direction control valve 51 of FIG.

  Thereby, the backup directional control valve 26 becomes a directional control valve for the additional hydraulic pump 10 from the first directional control valve 31 for the hydraulic pump 9A. That is, the backup directional control valve 26 is a directional control valve for another hydraulic pressure source that switches and controls the pressure oil of the additional hydraulic pump 10 serving as another hydraulic pressure source. Thus, in the first embodiment, when the attachment is the bucket 4C, the control valve device 21 can be configured with only the first direction control valve 31. On the other hand, when the attachment is the crusher 4G, the control valve device 21 can be configured by the first direction control valve 31 and the second direction control valve 51.

  Next, the first direction control valve 31 shown in FIG. 4 will be described. The first direction control valve 31 corresponds to the boom direction control valve 22, the arm direction control valve 23, the work tool direction control valve 24, or the turning direction control valve 25 in FIGS. 2 and 3. The first direction control valve 31 corresponds to the spare direction control valve 26 of FIG. 2, that is, the spare direction control valve 26 when the attachment is the bucket 4C. On the other hand, a second directional control valve 51 shown in FIG. 5 described later corresponds to the backup directional control valve 26 when the attachment is the crusher 4G.

  The first direction control valve 31 slides and displaces the spool 35 from the neutral position shown in FIG. 4 in the left and right directions to supply and discharge the pressure oil supplied to and discharged from the hydraulic actuator (for example, the boom cylinder 4D). It controls the flow rate. The first direction control valve 31 includes a valve casing 32 as a first valve casing, hydraulic pressure source side oil passages 33 and 33 as a first hydraulic pressure source side oil passage, and an actuator as a first actuator port. The first port 34, the spool 35 as the first spool, the one side supply passage 36 as the first one side supply passage, and the one side connection port 37 as the first one side connection port; The other side connection port 38 as the first other side connection port and the check valve 41 as the first check valve are configured.

  The valve casing 32 constitutes the valve body of the first directional control valve 31, and is also called, for example, a valve housing, a valve block, and a housing block. The valve casing 32 is provided with a spool slide hole 32A extending in the left and right directions. In the valve casing 32, annular oil grooves 32B and 32C are formed axially spaced apart on the peripheral wall side of the spool sliding hole 32A, and another annular oil oil is formed between the oil grooves 32B and 32C. Grooves 32D, 32D are formed. Further, in the peripheral wall of the spool sliding hole 32A, another oil groove 32E, 32E is formed at a position that is axially outside the oil grooves 32B, 32C.

  The oil grooves 32B, 32C among the oil grooves 32B, 32C, 32D, 32E are oil grooves on the supply / discharge side of the pressure oil, and are in communication with the actuator ports 34, 34 respectively. On the other hand, the oil grooves 32D, 32D are oil grooves on the high pressure side, and are in communication with the oil pressure source side oil passages 33, 33, respectively. The oil grooves 32E and 32E are oil grooves on the low pressure side, and communicate with the hydraulic oil tank 13, respectively.

  The pair of hydraulic pressure source side oil passages 33, 33 are provided in the valve casing 32. The pair of hydraulic pressure source side oil passages 33, 33 are separated in the axial direction of the spool sliding hole 32A. One side of the hydraulic pressure source side oil passages 33, 33 communicates with the oil grooves 32D, 32D, and the other side communicates with the one side connection port 37 and the other side connection port 38. The hydraulic pressure source side oil passages 33, 33 are connected to the hydraulic pumps 9A, 9B as one hydraulic pressure source via the check valve 41 and the one side supply passage 36.

  A pair of actuator ports 34, 34 are provided in the valve casing 32. The pair of actuator ports 34, 34 are separated in the axial direction of the spool sliding hole 32A with the pair of hydraulic pressure source side oil passages 33, 33 interposed therebetween. The actuator ports 34, 34 communicate with the oil groove 32 B or the oil groove 32 C on one side and open on the side of the valve casing 32 on the other side.

The other side of the actuator ports 34, 34 is connected to a hydraulic actuator. For example, when the hydraulic actuator is the boom cylinder 4D and the first direction control valve 31 is the boom direction control valve 22, the other side of one actuator port 34 is connected to the bottom side oil chamber of the boom cylinder 4D, the other actuator - the other side of the Tapoto 34 is connected to the rod side oil chamber of the boom cylinder da 4 D.

  The spool 35 is slidably fitted in the spool sliding hole 32A. The spool 35 communicates and shuts off between the pair of hydraulic pressure source side oil passages 33, 33 and the pair of actuator ports 34, 34, respectively. For example, when the hydraulic actuator is the boom cylinder 4D and the first direction control valve 31 is the boom direction control valve 22, the operation lever device for boom 4A operation is supplied to the hydraulic pilot units 44 and 47 described later. The spool 35 is axially displaced in the spool slide hole 32A according to the pilot pressure. As a result, the pair of hydraulic pressure source side oil passages 33, 33 can be communicated with and blocked from the pair of actuator ports 34, 34.

  The one side supply passage 36 is provided in the valve casing 32. The one side supply passage 36 extends in a direction orthogonal to the spool slide hole 32A. The one side supply passage 36 is connected to the hydraulic pump 9A or the hydraulic pump 9B which constitutes one hydraulic pressure source, and pressure oil is supplied from the hydraulic pump 9A or the hydraulic pump 9B.

  The one side connection port 37 connects the pair of hydraulic pressure source side oil passages 33 and 33 and the one side supply passage 36. On the other hand, the other side connection port 38 is provided in the valve casing 32 so as to face the one side connection port 37. The other side connection port 38 opens to the outer surface of the valve casing 32. The opening of the other side connection port 38 is covered by a lid 39. The lid 39 is fixed to the valve casing 32 by a bolt 40, for example.

  The check valve 41 is provided so that one side can be seated on the one side connection port 37 and the other side is inserted into the other side connection port 38. Between the check valve 41 and the lid 39, a biasing member 42 as a first biasing member is provided. The biasing member 42 is constituted by a spring member such as a coil spring, and biases the check valve 41 toward the one side connection port 37 side. Thereby, the check valve 41 allows the flow from the one side supply passage 36 to the pair of hydraulic pressure source side oil passages 33, 33, and the flow from the pair of hydraulic pressure source side oil passages 33, 33 to the one side supply passage 36 Cut off.

  That is, when the spool 35 is displaced from the neutral position, when one or the other actuator port 34 and the hydraulic pressure source side oil passage 33 communicate with each other, the hydraulic pressure is changed according to the load applied to the hydraulic actuator. When the pressure of the source side oil passage 33 becomes higher than the pressure of the one side supply passage 36, the check valve 41 is in the shut off position where it is seated at the one side connection port 37. Thereby, it is possible to prevent the pressure oil from flowing back from the hydraulic actuator to the hydraulic pumps 9A, 9B.

  One side cover 43 as a first one side cover is provided on one side surface (left side surface) of the valve casing 32. The one side cover 43 is formed, for example, in a cylindrical shape. The one side cover 43 is coaxial with the spool slide hole 32A, and constitutes a hydraulic pilot portion 44 of the first direction control valve 31. A spring 45 is disposed in the one-side cover 43 to always bias the spool 35 toward the neutral position.

  On the other hand, the other side cover 46 as the first other side cover is provided on the other side surface (right side surface) of the valve casing 32. The other side cover 46 is formed, for example, in a cylindrical shape. The other side cover 46 is coaxial with the spool sliding hole 32A, and constitutes a hydraulic pilot portion 47 of the first direction control valve 31. The first directional control valve 31 displaces the spool 35 in the axial direction of the spool sliding hole 32A according to the pilot pressure supplied from the operation lever device for operation to the hydraulic pilot parts 44 and 47, for example. The oil grooves 32B and 32C are selectively communicated with and blocked from the oil grooves 32D and 32D on the high pressure side or the oil grooves 32E and 32E on the low pressure side. Thereby, the first directional control valve 31 is switched from the neutral position.

  Next, the second direction control valve 51 shown in FIG. 5 will be described. The second directional control valve 51 corresponds to the auxiliary directional control valve 26 of FIG. 3, that is, the auxiliary directional control valve 26 when the attachment is the crusher 4G. In this case, the second direction control valve 51 includes the lid 39 of the first direction control valve 31, the check valve 41, and the biasing member 42, and the lid 59, the flow path blocking member 61, and the valve seat member 64 described later. And the check valve 65 and the biasing member 66.

  The second directional control valve 51 supplies and discharges the hydraulic actuator (more specifically, the work tool driving cylinder 4H) by slidingly displacing the spool 55 from the neutral position shown in FIG. 5 in the left and right directions. Control the direction and flow rate of pressure oil. The second direction control valve 51 includes a valve casing 52 as a second valve casing, hydraulic pressure source side oil passages 53 and 53 as a second hydraulic pressure source side oil passage, and an actuator as a second actuator port. -The spool 55 as a second spool, the one side supply passage 56 as a second one side supply passage, and the one side connection port 57 as a second one side connection port; , The other side connection port 58 as the second other side connection port, the other side supply passage 59A, the flow path blocking member 61, the valve seat member 64, and the check valve 65 as the second check valve It consists of

  The valve casing 52 constitutes the valve body of the second direction control valve 51, and is similar to the valve casing 32 of the first direction control valve 31. That is, in the valve casing 52, similarly to the valve casing 32, the spool slide hole 52A extending in the left and right directions, oil grooves 52B and 52C on the supply / discharge side of pressure oil, oil groove 52D on the high pressure side, Oil grooves 52E and 52E on the low pressure side 52D are provided. Oil grooves 52B and 52C are in communication with actuator ports 54 and 54, respectively. The oil grooves 52D, 52D are in communication with the hydraulic pressure source side oil passages 53, 53, respectively. The oil grooves 52E, 52E communicate with the hydraulic oil tank 13, respectively.

  The pair of hydraulic pressure source side oil passages 53, 53 are provided in the valve casing 52. The pair of hydraulic pressure source side oil passages 53, 53 are separated in the axial direction of the spool sliding hole 52A. One side of the hydraulic pressure source side oil passages 53 communicates with the oil grooves 52D, 52D, and the other side communicates with the one side connection port 57 and the other side connection port 58. The hydraulic pressure source side oil passages 53, 53 are connected to an additional hydraulic pump 10 serving as another hydraulic pressure source via the check valve 65, the other side supply passage 59A and the additional pipeline 12.

  A pair of actuator ports 54, 54 are provided in the valve casing 52. The pair of actuator ports 54, 54 are separated in the axial direction of the spool sliding hole 52A with the pair of hydraulic pressure source side oil passages 53, 53 interposed therebetween. The actuator ports 54, 54 communicate with the oil groove 52B or the oil groove 52C on one side and open on the side surface of the valve casing 52 on the other side.

  The other side of the actuator ports 54, 54 is connected to a hydraulic actuator. Specifically, the other side of one actuator port 54 is connected to the bottom side oil chamber of the work tool drive cylinder 4H, and the other side of the other actuator port 54 is the rod side oil of the work tool drive cylinder 4H Connected to the room.

  The spool 55 is slidably fitted in the spool slide hole 52A. The spool 55 communicates and shuts off between the pair of hydraulic pressure source side oil passages 53, 53 and the pair of actuator ports 54, 54, respectively. More specifically, the spool 55 axially displaces the inside of the spool slide hole 52A according to a pilot pressure supplied from, for example, an operation lever device for the crusher 4G to hydraulic pilot portions 68 and 71 described later. Do. As a result, the pair of hydraulic pressure source side oil passages 53, 53 can be communicated with and blocked from the pair of actuator ports 54, 54.

  The one side supply passage 56 is provided in the valve casing 52. The one side supply passage 56 extends in a direction orthogonal to the spool slide hole 52A. The one side supply passage 56 is connected to the hydraulic pump 9A or the hydraulic pump 9B constituting one hydraulic source similarly to the one side supply passage 36 of the first direction control valve 31, and from the hydraulic pump 9A or the hydraulic pump 9B. Pressure oil is supplied.

The one side connection port 57 connects the pair of hydraulic pressure source side oil passages 53 and 53 and the one side supply passage 56. On the other hand, the other side connection port 58 is provided in the valve casing 52 so as to face the one side connection port 57. The other side connection port 58 opens to the outer surface of the valve casing 52. The opening of the other side connection port 58 is covered by a lid 59. The lid 59 is fixed to the valve casing 52 by a bolt 60 , for example.

  Here, the lid 59 is provided with the other side supply passage 59A which is a through hole. The other side supply passage 59A is connected to the other side connection port 58. The other side supply passage 59A is to be an external input port, and the side opposite to the other side connection port 58 is connected to the additional conduit 12 to be an external conduit. That is, the other side supply passage 59A is connected to the additional hydraulic pump 10 that constitutes another hydraulic pressure source via the additional conduit 12. As a result, pressure oil is supplied to the other side supply passage 59A from another oil pressure source other than the one oil pressure source.

  The flow path blocking member 61 is provided across the one side connection port 57 and the other side connection port 58. That is, the flow path blocking member 61 has a valve body 61A on one side and a sleeve 61B on the other side, and the valve body 61A and the sleeve 61B are connected by a connecting portion 61C. The valve 61A is provided at the one side connection port 57. The sleeve 61 B is inserted into the other side connection port 58. The inner diameter side of the sleeve 61B and the inner diameter side of the connecting portion 61C form a bottomed check valve support hole 61D. A check valve 65 is inserted together with the biasing member 66 into the check valve support hole 61D.

  Here, the valve body 61A blocks the flow from the pair of hydraulic pressure source side oil passages 53, 53 to the one side supply passage 56. That is, in the flow path blocking member 61, the displacement in the axial direction is blocked by the lid 59 and the valve seat member 64 in a state where the valve body 61 </ b> A blocks the one side connection port 57. Therefore, the pressure oil in the one side supply passage 56 is prevented from flowing out to the pair of hydraulic pressure source side oil passages 53, 53 by the valve body 61A. That is, the valve body 61A of the flow path blocking member 61 always blocks the flow from the pair of hydraulic pressure source side oil passages 53, 53 to the one side supply passage 56, and from the one side supply passage 56 to the pair of hydraulic pressure sides The flow to the oil passages 53, 53 is always shut off. In this case, a seal groove 61A1 is provided all around the valve body 61A, and an O-ring 61A2 as a seal member is attached to the seal groove 61A1. The O-ring 61A2 seals oil-tight (liquid-tight) between the valve body 61A and the one-side connection port 57.

  On the other hand, sleeve openings 62 are provided in the sleeve 61B at two positions in the circumferential direction of the sleeve 61B. The sleeve opening 62 constantly communicates between the inner surface 61B1 and the outer surface 61B2 of the sleeve 61B. The sleeve opening 62 is configured by cutting out the sleeve 61B. Thus, an oil passage 63 (see FIG. 7) is formed between the notched portion (sleeve opening 62) of the sleeve 61B and the inner peripheral surface of the other side connection port 58. In this case, the flow passage area of the oil passage 63 formed by the inner peripheral surface of the other side connection port 58 and the sleeve opening 62 is the flow passage area of the other side supply passage 59A (and the oil on the inner diameter side of the valve seat member 64). Road area is more than).

  The valve seat member 64 is provided at the other side connection port 58. The valve seat member 64 is formed as a cylindrical member and is fitted into the other side connection port 58. One side of the valve seat member 64 is in contact with the lid member 59, and the other side is in contact with the sleeve 61 B of the flow path blocking member 61. Further, the other side of the valve seat member 64 is a valve seat 64A on which the check valve 65 is released and seated.

  Here, the valve seat member 64 regulates the position of the flow path blocking member 61. That is, in a state where the lid 59 is fixed to the valve casing 52 by the bolt 60, the valve seat member 64 regulates the axial position of the flow path blocking member 61. Specifically, with the axial dimension of the valve seat member 64, the valve body 61A of the flow path blocking member 61 closes the one side connection port 57 in a state where the lid 59 is fixed to the valve casing 52 with the bolt 60, The axial displacement of the flow path blocking member 61 is set to be blocked. In other words, the valve seat member 64 maintains the state in which the valve body 61A of the flow path blocking member 61 blocks the one side connection port 57.

The check valve 65 is provided so as to be detachable from the valve seat member 64. That is, one side of the check valve 65 is provided so as to be able to be seated on and off the valve seat 64 A of the valve seat member 64, and the other side is inserted into the check valve support hole 61 D of the flow path blocking member 61. A biasing member 66 as a second biasing member is provided between the check valve 65 and the bottom of the check valve support hole 61D. The biasing member 66 is formed of a spring member such as a coil spring, and biases the check valve 65 toward the valve seat member 64. Thereby, the check valve 65 permits the flow from the other side supply passage 59A to the pair of hydraulic pressure source side oil passages 53, 53, and the flow from the pair of hydraulic pressure source side oil passages 53, 53 to the other side supply passage 59A. Cut off.

  That is, when the spool 55 is displaced from the neutral position, one or the other actuator port 54 and the hydraulic pressure source side oil passage 53 communicate with each other, the hydraulic actuator (more specifically, the work tool driving cylinder When the pressure of the hydraulic pressure source side oil passage 53 becomes higher than the pressure of the other side supply passage 59A in accordance with the fluctuation of the load applied to 4H), the check valve 65 is in the blocking position where it is seated on the valve seat member 64. Thereby, it is possible to prevent the pressure oil from flowing back from the hydraulic actuator (more specifically, the work implement driving cylinder 4H) to the additional hydraulic pump 10.

  The one side cover 67 as a second one side cover, the hydraulic pilot portion 68, the spring 69, the other side cover 70 as a second other side cover, and the hydraulic pilot portion 71 of the first direction control valve 31. The first cover 43, the hydraulic pilot portion 44, the spring 45, the other cover 46, and the hydraulic pilot portion 47 are the same. The second directional control valve 51 displaces the spool 55 in the axial direction of the spool sliding hole 52A in accordance with the pilot pressure supplied from the operation lever device for the crusher 4G to the hydraulic pilot units 68 and 71, for example. The oil grooves 52B and 52C on the side are selectively communicated with and blocked from the oil grooves 52D and 52D on the high pressure side or the oil grooves 52E and 52E on the low pressure side.

  The hydraulic shovel 1 and the second direction control valve 51 according to the present embodiment have the above-described configuration, and the operation thereof will be described next.

  The operator of the hydraulic shovel 1 board the cab 7. As shown in FIGS. 1 and 2, when the attachment is a bucket 4C, when the engine 8 is started, the hydraulic pumps 9A and 9B are driven by the engine 8. The pressure oil discharged from the hydraulic pumps 9A and 9B is transferred to the left and right traveling hydraulic motors and the turning hydraulics according to the operation of the traveling control lever and pedal device provided in the cab 7 and the working control lever device. The motor 5, the boom cylinder 4D of the working device 4, the arm cylinder 4E, and the work cylinder 4F are supplied. Thereby, the hydraulic shovel 1 can perform traveling operation by the lower traveling body 2, swing operation of the upper swing body 3, excavating work by the work device 4, and the like.

  Further, as shown in FIG. 3, when the attachment is the crusher 4G, when the engine 8 is started, the hydraulic pumps 9A, 9B and the additional hydraulic pump 10 are driven by the engine 8. The pressure oil discharged from the additional hydraulic pump 10 is supplied to the work tool drive cylinder 4H in accordance with the operation of the control lever device for the crusher 4G. Thereby, hydraulic excavator 1 can perform dismantling work etc. by crusher 4G.

  Here, when the spool 55 of the second direction control valve 51 is displaced from the neutral position in the left and right directions, the pressure oil supplied from the additional hydraulic pump 10 to the other side supply passage 59A via the additional conduit 12 The check valve 65 disengages from the valve seat 64 A of the valve seat member 64 against the biasing force of the biasing member 66 based on the pressure of As a result, the pressure oil on the other side supply passage 59A side flows from between the valve seat member 64 and the check valve 65 into the sleeve 61B side of the flow path blocking member 61, and the hydraulic pressure through the sleeve opening 62 of the flow path blocking member 61. It flows out to the source side oil passage 53, 53 side.

Then, pressure oil in the hydraulic pressure source side oil passage 53 is supplied to the work tool drive cylinder 4H side through the actuator port 5 4 in communication with the hydraulic pressure source side oil passage 53. At this time, when the pressure in the hydraulic pressure source side oil passage 53 becomes higher than the pressure in the other side supply passage 59A with the fluctuation of the load applied to the work implement drive cylinder 4H, the pressure load and the biasing force of the biasing member 66 And the check valve 65 is seated on the valve seat 64A of the valve seat member 64. Thereby, it is possible to prevent the pressure oil from flowing back from the work implement drive cylinder 4H to the additional hydraulic pump 10 side.

  Next, when changing the attachment from the bucket 4C to the crusher 4G, the spare directional control valve 26 is changed from the first directional control valve 31 shown in FIG. 4 to the second directional control valve 51 shown in FIG. The procedure (method) of the work to be performed will be described.

  First, the lid 39, the check valve 41, and the biasing member 42 are removed from the first direction control valve 31 shown in FIG. 4 (first step). Next, the first direction control valve 31 with the lid 39, the check valve 41 and the biasing member 42 removed, the lid 59, the channel blocking member 61, the valve seat member 64 and the check valve 65 shown in FIG. And the biasing member 66 (second step). Then, the other side supply passage 59A of the lid 59 and the additional hydraulic pump 10 are connected by the additional pipeline 12 (third step). Thereby, the first directional control valve 31 shown in FIG. 4 is changed to the second directional control valve 51 shown in FIG. Thus, in the first embodiment, even if the spare directional control valve 26 is not removed from the hydraulic shovel 1, the spare directional control valve 26 and the check valve 41 for the hydraulic pump 9A are incorporated. The direction control valve 31 of 1 can be changed to the second direction control valve 51 incorporating the check valve 65 for the additional hydraulic pump 10.

  Thus, according to the first embodiment, an additional hydraulic pump 10 is used in place of the check valve 41 for the hydraulic pumps 9A and 9B in the valve casing 32 of the first direction control valve 31 serving as the existing valve casing. The check valve 65 can be built in.

  That is, in the second direction control valve 51 shown in FIG. 5, the flow path blocking member 61, the valve seat member 64 and the check valve 65 are provided in the one side connection port 57 and the other side connection port 58. In this case, the flow path blocking member 61 is regulated in position by the valve seat member 64 provided at the other side connection port 58, and one side of the flow path blocking member 61 becomes the valve body 61A and the other side. Is a sleeve 61B. Furthermore, a check valve 65 is provided between the flow passage blocking member 61 and the valve seat member 64, in other words, on the inner diameter side of the flow passage blocking member 61, so as to be able to be seated on the valve seat member 64. .

Therefore, the hydraulic pump 9A, one side connection port 3 7 (5 7) can incorporate a check valve 41 for 9B and on the other side connection port 3 8 (5 8) within the channel blocking member 61 and the valve seat Along with the member 64, a check valve 65 for the additional hydraulic pump 10 can be incorporated. In this case, the flow path blocking member 61, the valve seat member 64, and the check valve 65 do not need to be newly processed on the valve casing 32 (52), the one side connection port 37 (57) and the other side connection port 38 (58) can be incorporated. In other words, the shape of the valve casing 32 of the first direction control valve 31 that controls the pressure oil supplied through the one side supply passage 36 (56) and the pressure oil supplied through the other side supply passage 59A are controlled. The shape of the valve casing 52 of the second direction control valve 51 can be made common. Thereby, when manufacturing both the 1st direction control valve 31 and the 2nd direction control valve 51, reduction of the manufacturing cost by the ability to make the shape of valve casings 32 and 52 in common can be aimed at.

  Furthermore, when the first direction control valve 31 is changed to the second direction control valve 51, the operation of processing the valve casing 32 (52) (operation of changing the hole shape) can be omitted. Therefore, for example, the first direction control valve 31 can be changed to the second direction control valve 51 while the first direction control valve 31 is attached to the hydraulic shovel 1 to be attached. That is, with the first direction control valve 31 attached to the hydraulic shovel 1, the check valve 41 is removed from the first direction control valve 31, and the check valve 65 is It can be integrated with the valve seat member 64. Thereby, the operation | work which incorporates the check valve 65 can be done easily. That is, the operation of changing the first direction control valve 31 to the second direction control valve 51 can be easily performed.

  Furthermore, a sleeve opening 62 is provided in the sleeve 61 B of the flow path blocking member 61. Therefore, the pressure oil which has flowed into the sleeve 61 B side of the flow path blocking member 61 from between the valve seat member 64 and the check valve 65 passes through the sleeve opening 62 of the flow path blocking member 61 to the hydraulic source side oil paths 53, 53. leak. That is, the flow path of the pressure oil after passing the check valve 65 can be not the inner hole of the flow path blocking member 61 but the outer peripheral side, and the passage of the pressure oil can be secured by the sleeve opening 62.

  Therefore, the pressure loss can be reduced by securing the size of the sleeve opening 62 without processing such as increasing the inner diameter of the other side connection port 38 (58). As a result, also from this aspect, the one-side connection port 37 (57) and the other-side connection port 38 (58 (58) (58) can be obtained without newly processing the valve casing 32 (52). The flow path blocking member 61, the valve seat member 64, and the check valve 65 can be incorporated therein. That is, even if the valve casing 32 (52) is not subjected to new processing, it is possible to achieve both the incorporation of the check valve 65 and the reduction of the pressure loss.

  According to the first embodiment, the sleeve opening 62 of the flow path blocking member 61 is configured by cutting out the sleeve 61B, and the cut-out portion of the sleeve 61B and the inner peripheral surface of the other side connection port 58 And an oil passage 63 is formed therebetween. Therefore, the cross-sectional area (flow passage area) of the oil passage 63 can be easily secured, and the pressure loss can be reduced.

  According to the first embodiment, the valve body 61A of the flow passage blocking member 61 always blocks the flow from the hydraulic pressure source side oil passages 53, 53 to the one side supply passage 56, and the one side supply passage 56 The flow from the pressure source side to the oil pressure source side oil passages 53, 53 is always shut off. As a result, pressure oil can be supplied to the hydraulic pressure source side oil passages 53, 53 only from the additional hydraulic pump 10.

  According to the first embodiment, the flow passage area of the oil passage 63 formed by the inner peripheral surface of the other side connection port 58 and the sleeve opening 62 has the other side supply passage 59A (and the inner diameter of the valve seat member 64). It is configured to be more than the flow area of the side). Thereby, the pressure loss of the pressure oil flowing from the other side supply passage 59A (and the inner diameter side of the valve seat member 64) to the hydraulic pressure source side oil passage 53, 53 through the oil passage 63 can be reduced.

  Next, FIGS. 9 and 10 show a second embodiment. A feature of the second embodiment is that a plurality of grooves as sleeve openings are provided in the sleeve of the flow path blocking member. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

  The sleeve 81 of the flow path blocking member 61 is provided with grooves 82 as sleeve openings at six positions in the circumferential direction of the sleeve 81. The groove portion 82 constantly communicates between the inner surface 81 A and the outer surface 81 B of the sleeve 81. The groove 82 is formed by cutting out the sleeve 81, and an oil passage 83 is formed between the groove 82 and the inner peripheral surface of the other side connection port 58. In this case, the flow passage area of the oil passage 83 is equal to or larger than the flow passage area of the other side supply passage 59A (and the oil passage area on the inner diameter side of the valve seat member 64).

  In the second embodiment, a plurality of grooves 82 as described above are provided in the sleeve 81, and the basic operation is not particularly different from that according to the first embodiment described above. In particular, in the second embodiment, the contact position between the sleeve 81 and the valve seat member 64 can be prevented from being biased in the circumferential direction (can be uniformly contacted in the circumferential direction).

  Next, FIG. 11 shows a third embodiment. The feature of the third embodiment is that the lid and the valve seat member are integrally formed. In the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

  The lid 91 includes a main body 91A, and a projection 91B as a valve seat member that protrudes from the main body 91A toward the flow path blocking member 61. The main body 91A and the projection 91B are provided with a through hole 91C as another side supply passage which penetrates the main body 91A and the projection 91B. The projecting portion 91B is inserted into the other side connection port 58, and the projecting end of the projecting portion 91B is a valve seat 91D on which the check valve 65 is released and seated.

  In the third embodiment, the projecting portion 91B of the lid 91 as described above is used as a valve seat member of the check valve 65, and the basic action thereof is the same as that according to the first embodiment described above. There is no special difference. In particular, in the third embodiment, since the lid 91 also serves as a valve seat member, the number of parts can be reduced.

  Next, FIG. 12 shows a fourth embodiment. A feature of the fourth embodiment is that the flow path blocking member has the function of a check valve for one hydraulic pressure source. In the fourth embodiment, the same components as those in the first and third embodiments described above are designated by the same reference numerals, and the description thereof will be omitted.

  Similar to the flow path blocking member 61 of the first embodiment, the flow path blocking member 101 of the fourth embodiment includes the valve body 101A, the sleeve 101B, the connecting portion 101C, and the check valve support hole 101D. There is. In this case, the sleeve 101B of the flow path blocking member 101 of the fourth embodiment has a shorter axial dimension than the sleeve 61B of the flow path blocking member 61 of the first embodiment. Further, another biasing member 102 is provided between the projecting portion 91 B of the lid 91 serving also as the valve seat member and the flow path blocking member 101. Another biasing member 102 is formed of a spring member such as a coil spring and biases the flow path blocking member 101 toward the one side connection port 57.

  Thereby, the valve body 101A of the flow path blocking member 101 is provided so as to be able to be separated from and seated on the one side connection port 57. That is, the valve body 101A of the flow path blocking member 101 blocks the flow from the hydraulic pressure source side oil paths 53, 53 to the one side supply passage 56, and from the one side supply passage 56 to the pair of hydraulic pressure source side oil passages 53. , 53 are allowed to flow. The projecting portion 91B as a valve seat member regulates the position of the flow path blocking member 101, that is, the amount of displacement (stroke amount) in the axial direction. Also, another biasing member 102 can be omitted. That is, the check valve 65 may be biased toward the projecting portion 91 B by the biasing member 66 alone, and the flow path blocking member 101 may be biased toward the one side connection port 57.

  The fourth embodiment is configured to allow the flow from the one side supply passage 56 to the pair of hydraulic pressure source side oil passages 53, 53 by the flow path blocking member 101 as described above, and the basic action thereof There is no particular difference from the first embodiment described above. In particular, in the fourth embodiment, pressure oil from both the hydraulic pumps 9A and 9B and the additional hydraulic pump 10 can be supplied to the hydraulic pressure source side oil passages 53 and 53. That is, both the check valve (flow path blocking member 101) of the hydraulic pump 9A, 9B and the check valve 65 for the additional hydraulic pump 10 can be built in the one side connection port 57 and the other side connection port 58. it can. In this case, the flow rate of pressure oil supplied to the hydraulic actuator (more specifically, the work implement driving cylinder 4H) can be increased, and the operating speed of the hydraulic actuator can be increased.

  In each embodiment, the valve casings 32 and 52 of the directional control valves 22, 23, 24, 25 and 26 constituting the control valve device 21 are provided for each directional control valve 22, 23, 24, 25 and 26. The separate case has been described by way of example. However, the present invention is not limited thereto. For example, the valve casing (the valve casing 32 of the first direction control valve 31) of the arm direction control valve 23 and the valve casing (the first direction control of the spare direction control valve 26) The valve casing 32 of the valve 31 or the valve casing 52) of the second direction control valve 51 may be an integral valve casing. That is, the valve casings of the plurality of direction control valves may be formed as an integral valve casing.

  In each embodiment, the attachment of the hydraulic shovel 1 at the time of factory shipment is set as the bucket 4C, and then the attachment is changed from the bucket 4C to the crusher 4G at the maintenance plant and the additional hydraulic pump 10 is retrofitted. I mentioned to you. However, the present invention is not limited to this. For example, the attachment may be replaced with a crusher 4G and an additional hydraulic pump 10 may be attached from factory shipment. In this case, there is no need to change the first directional control valve to the second directional control valve (the second directional control valve may be manufactured). In this case, since the shapes of the valve casings of the first direction control valve and the second direction control valve can be made common, the manufacturing cost can be reduced. Furthermore, as an attachment different from a bucket, various attachments which require pressure oil, such as a breaker, a cutter, and a crusher other than the crusher 4G, can be used.

  In each of the embodiments, the additional hydraulic pump 10 is connected to the backup directional control valve 26, and the second directional control valve 51 is used as the backup directional control valve 26, as an example. However, the present invention is not limited to this. For example, the additional hydraulic pump 10 may be connected to the turning direction control valve 25 and the turning direction control valve 25 may be used as the second direction control valve 51. Alternatively, the boom direction control valve 22 and the arm direction control valve 23 may be used as the second direction control valve 51. That is, which one of the plurality of direction control valves constituting the control valve device is used as the first direction control valve or the second direction control valve depends on, for example, the specifications of the hydraulic shovel, the required performance, and the efficiency. It can be selected according to the etc.

  In each embodiment, the hydraulic shovel 1 was mentioned as an example and demonstrated as a construction machine. However, the present invention is not limited thereto, and various industrial machines including construction machines such as hydraulic cranes, wheel loaders and forklifts, in other words, various kinds of directional control valves (control valve devices) provided in hydraulic circuits. It can be widely applied to machines. Furthermore, it is needless to say that each embodiment is an exemplification, and partial replacement or combination of the configurations shown in the different embodiments is possible.

  According to the above embodiment, the check valve for another hydraulic pressure source can be built in the existing valve casing.

  (1). That is, the existing valve casing can incorporate a check valve for one hydraulic pressure source in the one side connection port and the other side connection port. On the other hand, in the embodiment, the flow path blocking member, the valve seat member, and the check valve are provided in the one side connection port and the other side connection port. In this case, the flow path blocking member is regulated in position by the valve seat member provided on the other side connection port, and one side of the flow path blocking member is a valve body and the other side is a sleeve. There is. Further, between the flow passage blocking member and the valve seat member, in other words, on the inner diameter side of the flow passage blocking member, the flow from the other side supply passage to the oil pressure source side oil passage is permitted. A check valve for blocking flow to the side supply passage is provided so as to be detachable from the valve seat member.

  For this reason, it is possible to incorporate a check valve for another hydraulic pressure source together with a flow path blocking member and a valve seat member in one side connection port and the other side connection port where the check valve for one hydraulic pressure source can be incorporated. it can. In this case, the flow path blocking member, the valve seat member, and the check valve can be incorporated into the one-side connection port and the other-side connection port without having to newly process the existing valve casing. In other words, the shape of the valve casing of the directional control valve for one hydraulic pressure source (that is, the directional control valve for controlling the pressure oil supplied through the one-side supply passage) and the directional control valve for the other hydraulic pressure source That is, the shape of the valve casing of the direction control valve that controls the pressure oil supplied through the other side supply passage can be made common. Thereby, when manufacturing both the direction control valve for one hydraulic pressure source and the direction control valve for the other hydraulic pressure source, it is possible to reduce the manufacturing cost because the shape of the valve casing can be made common.

  Furthermore, when changing the direction control valve for one hydraulic pressure source to the direction control valve for another hydraulic pressure source, the operation of processing the existing valve casing (operation of changing the hole shape) can be omitted. Therefore, for example, the direction control valve for one hydraulic pressure source can be changed to the direction control valve for another hydraulic pressure source while the direction control valve is attached to the mounting target (for example, a construction machine). That is, while the directional control valve is attached to the mounting object, the check valve for one hydraulic pressure source is removed from the directional control valve, the check valve for the other hydraulic pressure source, the flow path blocking member and It can be integrated with the valve seat member. Thereby, the work which incorporates the check valve for other hydraulic pressure sources can be done easily. That is, the operation of changing the direction control valve for one hydraulic pressure source to the direction control valve for another hydraulic pressure source can be easily performed.

  Furthermore, the sleeve of the flow path blocking member is provided with a sleeve opening that constantly communicates between the inner surface and the outer surface of the sleeve. For this reason, the pressurized oil that has flowed into the sleeve side of the flow path blocking member from between the valve seat member and the check valve flows out to the hydraulic pressure source side oil path through the sleeve opening of the flow path blocking member. That is, the flow path of the pressure oil after passing the check valve can be set to the outer peripheral side instead of the inner hole of the flow path blocking member, and the passage of the pressure oil can be secured by the sleeve opening.

  Therefore, pressure loss can be reduced by securing the size of the sleeve opening without processing such as increasing the inner diameter of the other side connection port. As a result, also from this aspect, without interrupting the existing valve casing (that is, without changing the shape of the hole), the flow path blocking member and valve in the one side connection port and the other side connection port A seat member and a check valve can be incorporated. That is, even if the existing valve casing is not subjected to a new process, it is possible to combine the check valve for another hydraulic pressure source and to reduce the pressure loss.

  (2). According to the embodiment, the sleeve opening is formed by notching the sleeve, and an oil passage is formed between the notched portion of the sleeve and the inner peripheral surface of the other side connection port. . For this reason, the cross-sectional area (flow passage area) of the oil passage can be easily secured, and the pressure loss can be reduced.

  (3). According to the embodiment, the valve body of the flow passage blocking member always blocks the flow from the hydraulic pressure source side oil passage to the one side supply passage, and the flow from the one side supply passage to the hydraulic pressure source side oil passage It is configured to always shut off. As a result, pressure oil can be supplied to the hydraulic pressure source side oil passage only from the other hydraulic pressure source.

  (4). According to the embodiment, the valve body of the flow passage blocking member blocks the flow from the hydraulic pressure source side oil passage to the one side supply passage, and the flow from the one side supply passage to the pair of hydraulic pressure source side oil passages The construction is to allow As a result, hydraulic oil from both the one hydraulic source and the other hydraulic source can be supplied to the hydraulic source side oil passage. That is, both the check valve for one hydraulic pressure source and the check valve for the other hydraulic pressure source can be incorporated in the one side connection port and the other side connection port. In this case, the pressure oil supply flow rate to the hydraulic actuator can be increased, and the operating speed of the hydraulic actuator can be increased.

  (5). According to the embodiment, the flow passage area of the oil passage formed by the inner peripheral surface of the other side connection port and the sleeve opening is configured to be equal to or larger than the flow passage area of the other side supply passage. As a result, it is possible to reduce the pressure loss of the pressure oil flowing from the other side supply passage to the oil pressure source side oil passage through the oil passage.

1 Hydraulic excavator (construction machine)
9A, 9B hydraulic pump (one hydraulic source)
10 additional hydraulic pumps (other hydraulic sources)
21 Control valve device 51 Second directional control valve 52 Valve casing 52A Spool slide hole 53 Hydraulic source side oil passage 54 Actuator port 55 Spool 56 One side supply passage 57 One side connection port 58 Other side connection port 59A Other side supply passage 61, 101 channel blocking member 61A, 101A valve body 61B, 81, 101B sleeve 61B1, 81A inner surface 61B2, 81B outer surface 62 sleeve opening 63, 83 oil passage 64 valve seat member 65 check valve 82 groove (sleeve opening)
91B Protruding part (valve seat member)
91C Through hole (other side supply passage)

Claims (3)

A valve casing provided with a spool sliding hole;
A pair of hydraulic pressure source side oil passages provided in the valve casing so as to be spaced apart in the axial direction of the spool sliding hole;
A pair of actuator ports provided on the valve casing so as to be separated in the axial direction of the spool sliding hole with the pair of hydraulic pressure source side oil passages interposed therebetween;
A spool slidably inserted in the spool sliding hole and communicating and blocking communication between the pair of hydraulic pressure source side oil passages and the pair of actuator ports, respectively;
One-side supply passage provided in the valve casing and supplied with pressure oil from one hydraulic source;
One side connection port for connecting the pair of hydraulic pressure source side oil passages and the one side supply passage;
Another side connection port provided on the valve casing opposite to the one side connection port and opening on the outer surface of the valve casing;
A directional control valve comprising: an other side supply passage connected to the other side connection port and supplied with pressure oil from another hydraulic source different from the one hydraulic source;
One side is a valve provided at the one side connection port and blocking the flow from the pair of hydraulic pressure source side oil passages to the one side supply passage, and the other side is inserted into the other side connection port to form a sleeve Flow path blocking member,
A valve seat member provided at the other side connection port for regulating the position of the flow path blocking member;
The valve seat member is provided so as to be able to be separated from and seated on the valve seat member to allow the flow from the other side supply passage to the pair of hydraulic pressure source side oil passages and to allow the flow from the pair of hydraulic pressure source side oil passages to the other side supply passage A check valve to shut off,
A sleeve opening provided in the sleeve of the flow path blocking member and constantly communicating between the inner surface and the outer surface of the sleeve ;
The valve body of the flow path blocking member always blocks the flow from the pair of hydraulic pressure source side oil passages to the one side supply passage, and from the one side feed passage to the pair of hydraulic pressure source side oil passages directional control valves, wherein the structure and the fact that it to block flow at all times.   The sleeve opening is constituted by notching the sleeve, and an oil passage is formed between the notched portion of the sleeve and the inner peripheral surface of the other side connection port. Direction control valve of the construction machine described.   The construction machine according to claim 1, wherein a flow passage area of an oil passage formed by the inner peripheral surface of the other side connection port and the sleeve opening is equal to or larger than the flow passage area of the other side supply passage. Direction control valve.

Images