JP2006036021A - Hydraulic drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To install a priority valve without providing a particular installation space outside a main hydraulic pump and without requiring any piping to be connected with the main hydraulic pump. <P>SOLUTION: A hydraulic drive device is equipped with the main hydraulic pump 1 and the priority valve 4 to supply the pressure oil discharged from the main pump 1 to at least either of the main line 2 and auxiliary line 3 selectively and supply to the main line 2 in priority, wherein the priority valve 4 is installed rigidly on the main pump 1. The priority valve 4 is positioned near a valve plate 14 installed in the main pump 1, and the housing 10 of the main pump 1 has an oil passage 17 to put a discharge port 16 in the valve plate 14 in communication with the center chamber 24 formed in the priority valve 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is provided in a construction machine such as a wheel loader or an industrial machine, and selectively supplies pressure oil of a main hydraulic pump to at least one of a main pipe line and an auxiliary pipe line and supplies it preferentially to the main pipe line. The present invention relates to a hydraulic drive device including a priority valve.

  There exists a thing shown by patent document 1 as this type of prior art. This prior art is provided in a power steering mechanism, and supplies a main hydraulic pump and pressure oil discharged from the main hydraulic pump to at least a main pipeline that is a steering circuit and an auxiliary pipeline that is provided separately from the main pipeline. A priority valve that is selectively supplied to one side and that is supplied preferentially to the main pipeline, a steering valve that incorporates a movable valve member that is guided by the pressure oil in the main pipeline and that can be rotated by a handle, and the steering valve And a steering cylinder that controls the direction of the tire.

This prior art supplies pressure oil discharged from the main hydraulic pump preferentially to the steering cylinder via the priority valve and the main pipe line at the time of steering operation, and the surplus flow rate includes the boom, arm, etc. via the auxiliary pipe line. Supplied to the work implement circuit that drives the work implement, and when the handle is not operated, pressure oil discharged from the main hydraulic pump is supplied to the auxiliary pipeline via the priority valve, enabling the work implement to be driven. Yes.
JP-A-6-313408

  In the conventional hydraulic drive device including the priority valve as described above, the priority valve is generally disposed at a predetermined position outside the main hydraulic pump, and the priority valve and the main hydraulic pump are connected by piping. ing.

  For this reason, in the prior art, a special space for installing the priority valve must be secured at a predetermined location outside the main hydraulic pump. In recent years, machines equipped with this type of hydraulic drive device, for example, construction machines such as a wheel loader, tend to be restricted by the installation space of hydraulic equipment and the like due to demands for downsizing the entire machine. For this reason, in the prior art, a priority valve must be installed via a fixture in a limited installation space, that is, in a narrow work area, and this priority valve installation work tends to be difficult. It was.

  In addition, the above-described conventional technology requires a fixture for installing the priority valve at a predetermined location as described above, and further requires a pipe for connecting the priority valve to the main hydraulic pump, resulting in an increase in the number of parts. Cheap. In addition, the installation work of the priority valve and the piping work are necessary, so that the total number of installation work steps is likely to increase. For these reasons, the prior art has a problem that the production cost is high.

  The present invention has been made from the above-described prior art, and its purpose is to provide priority without providing a special installation space outside the main hydraulic pump and without requiring piping connected to the main hydraulic pump. An object of the present invention is to provide a hydraulic drive device in which a valve can be installed.

  In order to achieve the above object, the present invention selectively supplies a main hydraulic pump and pressure oil discharged from the main hydraulic pump to at least one of a main pipeline and an auxiliary pipeline, and supplies the main pipeline to the main pipeline. In the hydraulic drive apparatus including the priority valve to be supplied with priority, the priority valve is provided integrally with the main hydraulic pump.

  In the present invention configured as described above, since the priority valve is provided integrally with the main hydraulic pump, it is not necessary to provide a special installation space for the priority valve outside the main hydraulic pump. The work of providing the priority valve integrally with the main hydraulic pump can be performed simultaneously with the production of the main hydraulic pump and is simple.

  In addition, a fixture for fixing the priority valve to a predetermined location outside the main hydraulic pump, piping for connecting the priority valve to the main hydraulic pump, and the like become unnecessary, and the number of parts can be reduced by these. In addition, since the complicated installation work for installing the priority valve at a predetermined location outside the main hydraulic pump and the piping work for connecting the priority valve to the main hydraulic pump are not required, the total number of installation work steps can be reduced. it can.

  According to the present invention, in the above invention, the priority valve is disposed in the vicinity of a valve plate provided in the main hydraulic pump.

  According to the present invention, in the above invention, the housing of the main hydraulic pump has an oil passage that communicates a discharge port of the valve plate and a chamber formed in the priority valve.

  Further, the present invention provides a steering valve having a movable valve member that is guided by the pressure oil in the main pipe and rotated by a handle, and is operated by the pressure oil supplied from the steering valve. A power steering mechanism having a steering cylinder to be controlled is provided.

  According to the present invention, in the above invention, the priority valve housing is provided with a tail hose port to which a tail hose provided for suppressing pressure pulsation in the main pipe line is connected.

  In the present invention, since the priority valve is provided integrally with the main hydraulic pump, the priority valve is provided without providing a special installation space outside the main hydraulic pump and without requiring piping connected to the main hydraulic pump. Can be placed. Therefore, the priority valve can be easily installed.

  In addition, fixtures and piping associated with the priority valve are not required, and the total number of parts can be reduced as compared with the prior art. Furthermore, since complicated installation work and piping work related to the priority valve are not required, the total number of installation work steps can be reduced as compared with the prior art. As a result, the production cost can be reduced compared to the prior art.

  Furthermore, the conventional tail hose is generally provided in the discharge line of the main hydraulic pump, but when the main hydraulic pump and the priority valve are integrated, the discharge line of the main hydraulic pump is not easily exposed to the outside. Become. According to the present invention, the tail hose can be easily provided by providing the housing of the priority valve with the tail hose port to which the tail hose provided for suppressing the pressure pulsation in the main pipe line is connected.

  The best mode for carrying out the hydraulic drive apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a hydraulic circuit diagram showing the overall configuration of an embodiment of a hydraulic drive device according to the present invention. The present embodiment shown in FIG. 1 is provided, for example, in a steering mechanism of a wheel loader. The main hydraulic pump 1 and the pressure oil discharged from the main hydraulic pump 1 are supplied to at least the main pipeline 2 and the auxiliary pipeline 3. A priority valve 4 is provided which is selectively supplied to one side and supplied preferentially to the main pipeline 2. The priority valve 4 includes a slidable spool 5. One end of the spool 5 is provided with a control chamber 22 in which a spring 21 for biasing the spool 5 is arranged, and the other end is provided with a force due to the force of the spring 21 and the pressure oil pressure applied to the control chamber 22. And a control chamber 23 into which pressure oil that gives a force that counteracts the sum is guided.

  Also, a steering valve 7 having a movable valve member 8 that is guided by pressure oil in the main pipe line 2 and can be rotated around an axis by a handle (not shown) connected to the rod 8a, and a pressure supplied from the steering valve 7. And a steering cylinder 6 that is operated by oil and controls the direction of a tire (not shown). The movable valve member 8 of the steering valve 7 and the bottom chamber of the steering cylinder 6 are connected by a conduit 40, and the movable valve member 8 and the rod chamber of the steering cylinder 6 are connected by a conduit 41.

  In the priority valve 4, a safety valve that controls the load pressure of the steering cylinder 6 so as not to exceed a certain pressure, that is, a relief valve 42, and a filter 43 that keeps the pressure oil that passes through the relief valve 42 clean are arranged. It is. Further, the housing 20 of the priority valve 4 is provided with a tail hose port 50 communicating with the oil passage 17 on the discharge side of the main hydraulic pump 1, and the tail hose port 50 has a tail that suppresses pressure pulsation in the main pipe 2. A hose 51 is connected.

  The steering valve 7 and the tank 44 are connected by a return pipe 45, and a filter 46 that keeps the oil guided to the return pipe 45 clean is also arranged in the return pipe 45. Note that the discharge pressure of the main hydraulic pump 1 is defined by the main relief valve 47. Further, pressure oil is guided to a work machine circuit 9 that drives a work machine including a boom, an arm, and the like (not shown) by the auxiliary pipe 3 described above.

  FIG. 2 is a cross-sectional view showing a main hydraulic pump and a priority valve constituting main parts of the present embodiment, and FIG. 3 is a plan view including a cross-sectional view of part A in FIG. As shown in FIGS. 2 and 3, the present embodiment is characterized in that the priority valve 4 is provided integrally with the main hydraulic pump 1.

  As shown in FIG. 2, the main hydraulic pump 1 includes a drive shaft 11 that is rotatably accommodated in a housing 10 that forms a main body, and rotates integrally with the drive shaft 11 to form a plurality of cylinders in the circumferential direction. The cylinder block 12, a piston 13 slidably accommodated in each cylinder of the cylinder block 12, and a valve plate 14 fixed to the housing 10 and in sliding contact with the cylinder block 12. The valve plate 14 is slid by the suction port 15 into which the oil in the tank 44 is sucked, and the cylinder block 12 that rotates integrally with the drive shaft 11. And are formed.

  An oil passage 17 communicating with the discharge port 16 of the valve plate 14 is formed in the housing 10 of the main hydraulic pump 1. The priority valve 4 is disposed in the vicinity of the valve plate 14. As will be described later, a central chamber 24 communicating with the oil passage 17 is formed in the housing 20 of the priority valve 4.

  FIG. 4 is an enlarged view of the priority valve portion shown in FIG. As shown in FIG. 4, the housing 20 that slidably houses the spool 5 of the priority valve 4 is provided with a discharge port of the valve plate 14 through the oil passage 17 formed in the housing 10 of the main hydraulic pump 1 described above. A central chamber 24 that communicates with the central chamber 24, a central chamber 24 that can communicate with the central chamber 24, a chamber 26 that communicates with the main pipeline supply port CF connected to the main pipeline 2, and a central chamber 24. And a chamber 28 communicating with the auxiliary pipeline supply port EF connected to the auxiliary pipeline 3 described above.

  The spool 5 slidably disposed in the housing 20 is formed at one end of a small diameter portion 33 facing the central chamber 24, and controls the main line side control edge 29 that controls the flow of pressure oil supplied to the main line 2. And a second large diameter portion 32 having an auxiliary conduit side control edge 31 that is formed at the other end of the small diameter portion 33 and that controls the flow of pressure oil supplied to the auxiliary conduit 3. It has. The first large diameter portion 30 described above faces the chamber 26, and the second large diameter portion 32 faces the chamber 28.

  In this embodiment configured as described above, when a handle (not shown) is not operated and the movable valve member 8 of the steering valve 7 is held at the neutral position as shown in FIG. The control chamber 22 in which 21 is disposed communicates with the tank 44 via the return line 45 and becomes a low pressure, and the low pressure is also given to the control chamber 23. Therefore, the spool 5 is maintained in the state shown in FIG. When the pressure oil P is discharged from the main hydraulic pump 1 in this state, the pressure oil is guided to the control chamber 23 at the other end of the spool 5 of the priority valve 4, and the pressure in the control chamber 23 becomes equal to or higher than a predetermined pressure. Sometimes the spool 5 is switched to the right position in FIG. 1 against the force of the spring 21.

  That is, due to the pressure oil pressure applied to the control chamber 23 of the priority valve 4 shown in FIG. 4, the spool 5 shown in FIG. 4 slides leftward from the state shown in FIG. And communicate. Therefore, the pressure oil P introduced into the oil passage 17 from the discharge port 16 of the valve plate 14 of the main hydraulic pump 1 shown in FIG. 2 flows along the outer periphery of the small diameter portion 33 disposed in the central chamber 24, It is led from the central chamber 24 to the chamber 28 and supplied from the auxiliary pipeline supply port EF to the auxiliary pipeline 3 shown in FIG. As a result, the pressure oil P is supplied from the auxiliary pipeline 3 to the work machine circuit 9 shown in FIG. 1, and the work machine (not shown) can be driven.

  Further, as shown in FIG. 1, the movable valve member 8 of the steering valve 7 is held at the neutral position, and the switching position of the spool 5 of the priority valve 4 is held at the left position shown in FIG. When a handle (not shown) is operated in a predetermined direction and the movable valve member 8 of the steering valve 7 shown in FIG. 1 is switched from the neutral position shown in FIG. 1 to the right position, for example, the main pipe is passed through the movable valve member 8. The passage 2 communicates with the conduit 41, and the load pressure of the conduit 41 is applied to the control chamber 22 in which the spring 21 is disposed via the load pressure port LS of the priority valve 4. Therefore, the spool 5 of the priority valve 4 depends on the magnitude relationship between the sum of the force of the spring 21 and the pressure oil pressure applied to the control chamber 22 and the force of the pressure oil pressure applied to the control chamber 23. Slide appropriately.

  That is, as the handle is operated, the spool 5 of the priority valve 4 is held in the state shown in FIG. 4, and the pressure oil P discharged from the main hydraulic pump 1 and guided to the oil passage 17 is supplied to the central chamber 24. Then, it flows along the outer periphery of the small diameter portion 33, is led from the central chamber 24 to the chamber 26, and is supplied from the chamber 26 to the main pipeline 2 shown in FIG. 1 via the main pipeline supply port CF. The pressure oil P supplied to the main pipeline 2 is guided to the pipeline 41 from the right position of the movable valve member 8 of the steering valve 7 and supplied to the rod chamber of the steering valve 6. The pressure oil flowing out from the bottom chamber of the steering cylinder 6 into the pipe line 40 is returned to the tank 44 via the right position of the movable valve member 8 of the steering valve 7 and the return pipe line 45. As a result, the steering cylinder 6 contracts. Due to the contraction of the steering cylinder 6, a tire (not shown) is moved in one direction so as to be inclined with respect to the previous installation direction.

  After that, when the force due to the pressure oil pressure guided to the control chamber 23 of the priority valve 4 becomes larger than the force on the control chamber 22 side, the spool 5 of the priority valve 4 moves to the left in FIG. 24 communicates with the chamber 28. As a result, the surplus flow rate of the pressure oil P of the main hydraulic pump 1 supplied as described above is led from the central chamber 24 to the chamber 28, and from this chamber 28 through the auxiliary pipe supply port EF in FIG. Supplied to the auxiliary line 3. As a result, the working machine can be driven as described above.

  During this operation, the upstream pressure of the steering valve 7 is guided to the control chamber 23 of the priority valve 4, and the downstream pressure of the steering valve 7 is guided to the control chamber 22 via the load pressure port LS. The spool 5 of the valve 4 slides according to the differential pressure between the upstream pressure and the downstream pressure of the steering valve 7. That is, the priority valve 4 functions as a pressure compensation valve. Therefore, the pressure compensation function of the priority valve 4 supplies the steering cylinder 6 with a flow rate corresponding to the amount of rotation of the movable valve member 8 of the steering valve 7, that is, the amount of operation of the steering wheel, regardless of fluctuations in the load pressure of the steering cylinder 6. can do.

  When a handle (not shown) is operated in the opposite direction, the movable valve member 8 of the steering valve 7 shown in FIG. 1 is switched from the neutral position shown in FIG. Is preferentially supplied to the bottom chamber of the steering cylinder 6 via the conduit 40, and the steering cylinder 6 is extended so that a tire (not shown) is tilted in the opposite direction. The operation of the priority valve 4 during such operations is substantially the same as described above.

  According to the present embodiment configured as described above, since the priority valve 4 is provided integrally with the main hydraulic pump 1, it is necessary to provide a special installation space for the priority valve 4 outside the main hydraulic pump 1. do not do. The operation of providing the priority valve 4 integrally with the main hydraulic pump 1 can be performed simultaneously when the main hydraulic pump 1 is manufactured, for example, and is simple.

  Further, the fixture for fixing the priority valve 4 to a predetermined location outside the main hydraulic pump 1 and the piping for connecting the priority valve 4 to the main hydraulic pump 1 are not required, thereby reducing the total number of parts. Can do. Further, since the complicated installation work for installing the priority valve 4 at a predetermined location outside the main hydraulic pump 1 and the piping work for connecting the priority valve 4 to the main hydraulic pump 1 are not required, the total number of installation work steps can be reduced. Can be reduced. For these reasons, the present embodiment can reduce the production cost.

  Furthermore, by providing the tail hose port 50 for connecting the tail hose 51 to the housing 20 of the priority valve 4, the tail hose 51 can be easily provided even when the main hydraulic pump 1 and the priority valve 4 are integrated. it can.

1 is a hydraulic circuit diagram showing an overall configuration of an embodiment of a hydraulic drive device according to the present invention. It is sectional drawing which shows the main hydraulic pump and priority valve which comprise the principal part of this embodiment. It is a top view including sectional drawing of the A section of FIG. FIG. 4 is an enlarged view of a priority valve portion shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main hydraulic pump 2 Main pipeline 3 Auxiliary pipeline 4 Priority valve 5 Spool 6 Steering cylinder 7 Steering valve 8 Movable valve member 9 Working machine circuit 10 Housing 14 Valve plate 15 Suction port 16 Exhaust port 17 Oil channel 20 Housing 21 Spring 22 Control Chamber 23 Control chamber 24 Central chamber 26 Chamber 28 Chamber 29 Main conduit side control edge 30 First large diameter portion 31 Auxiliary conduit side control edge 32 Second large diameter portion 33 Small diameter portion 50 Tail hose port 51 Tail hose CF Main conduit supply port EF Auxiliary pipeline supply port LS Load pressure port

Claims (5)

Hydraulic pressure provided with a main hydraulic pump, and a priority valve that supplies pressure oil discharged from the main hydraulic pump selectively to at least one of the main pipeline and the auxiliary pipeline, and preferentially supplies the main pipeline to the main pipeline In the drive device,
A hydraulic drive apparatus, wherein the priority valve is provided integrally with the main hydraulic pump. In the invention of claim 1,
A hydraulic drive device, wherein the priority valve is disposed in the vicinity of a valve plate provided in the main hydraulic pump. In the invention of claim 2,
The hydraulic drive device characterized in that the housing of the main hydraulic pump has an oil passage for communicating the discharge port of the valve plate and the chamber formed in the priority valve. In the invention according to any one of claims 1 to 3,
A power steering system including a steering valve having a movable valve member guided by pressure oil in the main pipe and rotatable by a handle, and a steering cylinder which is operated by the pressure oil supplied from the steering valve and controls the direction of the tire. A hydraulic drive device provided in the mechanism. In the invention according to any one of claims 1 to 4,
A hydraulic drive device comprising a tail hose port to which a tail hose provided for suppressing pressure pulsation in the main pipe line is connected to a housing of the priority valve.

Images