CN104696181A - Pump for closed-circuit configuration - Google Patents

Abstract

A multi-port component (70) comprises a cylinder seat which is rotatingly disposed a housing (108) and consists of a plurality of cylinder seats of hydraulic cylinders (122) and a plurality of ports which is fixedly disposed on the valve plate (116) of the housing (108). A part of the ports are connected to the pressure chamber of the cantilever hydraulic cylinder, and the left are connected to an oil tank. A V-shaped groove which turns smaller forward is disposed at the end of each port opening which is at the same side of the rotation direction of the cylinder seat (112). The v-shaped grooves which are respectively disposed at the piston upper dead center and at the piston lower dead center are made bigger, while the v-shaped grooves which are disposed between the piston upper dead center and the piston lower dead center are made smaller.

Description

Sealing loop forming pump

Technical field

The present invention relates to selectively to the sealing loop forming pump of a pair pressure chamber's discharge action oil of the piston both sides of oil hydraulic actuator, for forming as the sand such as excavator, the rotary blade lifts such as backhoe etc., working machine or aerial ladder apparatus etc. are with the loop comprising oil hydraulic actuator of the vehicle of lifting transmission device over the ground.

Background technique

In the past, the excavator such as backhoe as working machine was over the ground arranged on delvers such as scraper bowl or shovel forks on car body through cantilever or suspension rod etc., makes delver action, carry out digging operation thus through oil hydraulic actuators such as oil hydraulic cylinders.Such as, the backhoe as the excavator comprising hydraulic operation device is just recorded in Japanese Patent Application Publication JP 2000-319942 publication.

When the backhoe of Japanese Patent Application Publication JP 2000-319942 publication, between cantilever and turntable, be provided with boom cylinder, the flexible cantilever that can make of boom cylinder rotates up and down.Cantilever elevation switching valve is connected on boom cylinder, through master control oil circuit, main control valve is connected on the operation unit of this switching valve.Master control oil pressure is supplied from oil pressure pump to main control valve.

As prior art document related to the present invention, except Japanese Patent Application Publication JP 2000-319942 publication, also have Japanese Patent Application Publication Unexamined Patent 10-169547 publication, Japanese Patent Application Publication JP 2000-97146 publication.

When the hydraulic operation device being used for that boom cylinder is stretched recorded in Japanese Patent Application Publication JP 2000-319942 publication, one of the oily pressure chamber from the piston both sides of boom cylinder of action square pressure chamber discharges, and this action oil is discharged to fuel tank.Therefore, there is large pipe arrangement loss in discharge portion branch when it is discharged.That is, the oil hydraulic circuit comprising boom cylinder is open loop.

For this, loop is made in the oil hydraulic circuit comprising the oil hydraulic cylinder such as transmission device and boom cylinder, the pressure chamber turning back to the opposite side of oil hydraulic cylinder at least partially through pump of the action oil that one of the pressure chamber of the piston both sides from oil hydraulic cylinder square pressure chamber is ejected, thus loss when action oil is discharged can be reduced.In this case, because the compression area of the pressure chamber of oil hydraulic cylinder both sides is different, so the residual flow produced in oil circuit between pressure at both sides room and pump is discharged by remaining expulsion valve.Particularly when loop is made in the oil hydraulic circuit that the action of the lifting oil hydraulic cylinder of the boom cylinder of the vehicle of the band such as backhoe lifting transmission device etc. is used, the weight of weight when piston can utilize the deadweight of lifting unit or a part for lifting unit to keep the weights such as soil etc., the suction of the energy of the action oil from side pressure chamber discharge for the action oil of the pressure chamber to the opposing party.That is, potential energy can be utilized to reduce the energy consumption of the power sources such as the motor of driven pump.But, when using remaining expulsion valve like this, when the rotating speed of motor or acceleration uprise, remaining expulsion valve and the path crushing between remaining expulsion valve and the oil circuit leading to oil hydraulic cylinder make the pressure of pump sucting reduce, result, in pump, produce the stretching speed that air pocket and oil hydraulic cylinder do not reach expectation, likely make abnormal sound or abnormal vibrations become large simultaneously.That is, the stretching speed of oil hydraulic cylinder likely changes with the change of the discharge direction of pump.

For this, consideration need not remaining expulsion valve, replaces, pump is made the multiport pump of the multiport with more than three, the section ports of multiport pump is connected to fuel tank, thus the residual oil of the residual flow produced in oil circuit is discharged in fuel tank.Also consider multiport pump to make following structure, that is, make the cylinder seat with multiple oil hydraulic cylinder opposite shell rotate, each oil hydraulic cylinder is cyclically communicated to each port along with the rotation of cylinder seat.But along with the rotation of cylinder seat, become in the oil hydraulic cylinder of exhaust end once the action oil of high pressure flows into rapidly from the port becoming exhaust end, port periphery will produce air pocket, and becomes pump noise and vibrate the large reason of change.In the formation that above-mentioned Japanese Laid-Open Patent Application JP 2000-319942 publication, Japanese Laid-Open Patent Application Unexamined Patent 10-169547 publication, Japanese Laid-Open Patent Application JP 2000-97146 publication are recorded, all do not show the means can eliminating above-mentioned disadvantage.

Summary of the invention

The object of the invention is in sealing loop forming pump, when forming three multiport pumps with upper end-hole, reduce pump noise and vibration.

Relating to sealing loop forming pump of the present invention is a kind ofly be used for forming the loop comprising oil hydraulic actuator, and selectively to the sealing loop forming pump of a pair pressure chamber's discharge action oil of the piston both sides of oil hydraulic actuator; Wherein, possess shell, rotatably configure in the enclosure and be provided with multiple oil hydraulic cylinder cylinder seat, be reciprocally separately positioned on the multiple pistons in multiple oil hydraulic cylinder, the movable swash plate that each piston can be moved back and forth in each oil hydraulic cylinder with the rotation of cylinder seat movably and be formed in the multiple ports of more than 3 on shell or fixing other components in the enclosure; Multiple port comprise the side being connected to a pair pressure chamber connecting port, side pressure chamber, be connected to the connecting port, opposite side pressure chamber of the opposite side of a pair pressure chamber and be connected to the fuel tank connecting port of fuel tank; Each oil hydraulic cylinder can be communicated on each port with the rotation of cylinder seat selectively; Multiple port also possesses and is arranged on each port surface to the end of the side opening end of oil hydraulic cylinder, namely with the end of cylinder seat sense of rotation homonymy and the otch gradually little towards front end; The cylinder seat sense of rotation length of the otch of piston top dead center position is arranged on, with the cylinder seat sense of rotation same length of otch being arranged on piston lower dead point position in the otch of each port; Be arranged on the cylinder seat sense of rotation length of the otch of position between piston top dead center position and lower dead point position, be less than the cylinder seat sense of rotation length of the otch being arranged on piston top dead center position and the otch being arranged on piston lower dead point position.

According to above-mentioned sealing loop forming pump, the cylinder seat being provided with multiple oil hydraulic cylinder can be made to rotate relative to shell, and possess the multiple ports of more than 3 be formed on shell or fixing other components in the enclosure; Multiple port comprises the connecting port, side pressure chamber of the side being connected to a pair pressure chamber, the connecting port, opposite side pressure chamber being connected to the opposite side of a pair pressure chamber and the fuel tank connecting port be connected on fuel tank; Each oil hydraulic cylinder can be communicated on each port with the rotation of cylinder seat selectively; So can enough form closed oil hydraulic circuit by the part comprising sealing loop forming pump and oil hydraulic actuator.Therefore, through sealing loop forming pump, the excess oil that closed oil hydraulic circuit produces is discharged in fuel tank, thus reduces pipe arrangement oil consumption.Multiple port also possess be arranged on the opening end of the side facing with the oil hydraulic cylinder of each port, with the end of cylinder seat sense of rotation homonymy and the otch gradually little towards front end; The cylinder seat sense of rotation same length of the otch being arranged on piston top dead center position in the otch of each port and the otch being arranged on piston lower dead point position; Be arranged on the cylinder seat sense of rotation length of the otch of position between piston top dead center position and lower dead point position, be less than the cylinder seat sense of rotation length of the otch being arranged on piston top dead center position and the otch being arranged on piston lower dead point position.Therefore, in the oil hydraulic cylinder that the action oil of high pressure becomes exhaust end along with the rotation of cylinder seat flows into from the port becoming exhaust end, the size of otch along with the rotation of cylinder seat gradually large towards the end of port.So prevent the action oil of high pressure to flow in oil hydraulic cylinder hastily, thus inhibit the generation of air pocket, reduce pump noise and vibration.And, be arranged on the otch forming section of position between piston top dead center position and lower dead point position, with be arranged on piston top dead center position and compare with the otch forming section of lower dead point position, faced by the travelling speed of piston faster, action oil is higher to the inflow velocity in oil hydraulic cylinder.Therefore, the length reducing otch just more effectively obtains otch and forms effect, namely suppresses the generation of air pocket and the reduction of pump noise and vibration.

In sealing loop forming pump of the present invention, each port is preferably formed in and is arranged between shell and cylinder seat and is fixed on the valve plate on shell.

In sealing loop forming pump of the present invention, fuel tank connecting port or connecting port, side pressure chamber are preferably separated into the separation port of two along the sense of rotation of cylinder seat, and in the sense of rotation along cylinder seat, connecting port, side pressure chamber or fuel tank connecting port are configured between two separation ports.

In sealing loop forming pump of the present invention, oil hydraulic actuator is best power of by gravity, piston being given to the direction conjugated to side in use.

According to above-mentioned formation, utilize potential energy that the energy of the action oil of discharging from the side pressure chamber forming oil hydraulic actuator is used as the energy to pressure chamber's suction action oil of the opposing party, thus the energy consumption of the power sources such as the motor of driven pump can be reduced.

If adopt sealing loop forming pump of the present invention, when the multiport pump of formation 3 with upper end-hole, pump noise and vibration can be alleviated.

Accompanying drawing explanation

Fig. 1 is the band lifting transmission device vehicle of the sealing loop forming pump comprising embodiments of the present invention and the sketch map of backhoe.

Fig. 2 is the overall diagram of the oil hydraulic circuit of the sealing loop forming pump comprising one of embodiments of the present invention example.

Fig. 3 is the circuit diagram of the part A representing Fig. 2 in detail.

Fig. 4 is the sectional view representing the sealing loop forming pump of one of embodiments of the present invention example and an object lesson of multiport pump assembly.

Fig. 5 is stereogram valve plate being arranged on the state on the saddle of the port shown in Fig. 4.

Fig. 6 is the B-B sectional view of Fig. 4.

Fig. 7 is the diagram of the section of the saddle of port and the installation position of valve plate in Fig. 4.

Fig. 8 is the C-C sectional view of Fig. 4.

Fig. 9 takes out valve plate from Fig. 8, represents the diagram of the magnitude relationship of the otch that multiple port is formed.

Figure 10 represents to eliminate valve plate and the end view drawing of the saddle of the port of one of situation arranging otch example on multiple ports of directly being formed on the saddle of port.

Figure 11 is formed in the diagram of the first case of other examples of the multiple ports on the saddle of port.

Figure 12 is formed in the diagram of the second case of other examples of the multiple ports on the saddle of port.

Figure 13 is the circuit diagram of the first case of other examples of the part A representing Fig. 2.

Figure 14 is circuit diagram shown centered by the part being different from Fig. 3 in the second case of other examples of the part A of Fig. 2.

Figure 15 is the schematic partial sectional view of the multiport pump assembly of other examples of embodiments of the present invention.

Figure 16 is the view seen to the right from the left side of Figure 15 take out valve plate from Figure 15 after.

Figure 17 is the D-D sectional view of Figure 15.

Embodiment

Embodiments of the present invention are described in detail below with accompanying drawing.It is the diagram of one of embodiments of the present invention example from Fig. 1 to Fig. 9.As shown in Figure 1, with the vehicle of lifting transmission device of sealing loop forming pump and the backhoe 10 that comprise embodiments of the present invention, possess the traveling gear 12 comprising pairing left and right crawler belt, the upside being rotatably installed in traveling gear 12 turntable 14 and be arranged on the cockpit 16 of upside of turntable 14.Cockpit 16 comprises the operation unit such as driver's seat and operating stem.On the top of turntable 14, the front of cockpit 16 is provided with excavating machine 18.Excavating machine 18 comprises the first cantilever 20, second cantilever 22 and the 3rd cantilever 24.The base portion of the first cantilever 20 is arranged on turntable 14, can before and after and rotate up and down; Second cantilever 22 is supported on the front end of the first cantilever 20, can left-right rotation; 3rd cantilever 24 is supported on the front end of the second cantilever 22, can before and after and rotate up and down.Between the first cantilever 20 and turntable 14, be provided with boom cylinder 26, flexible first cantilever about 20 that can make of boom cylinder 26 rotates.

Between the first cantilever 20 and the 3rd cantilever 24, be provided with offset arm 28, be parallel to the second cantilever 22; Be configured with between the second cantilever 22 and the 3rd cantilever 24 and offset oil hydraulic cylinder 30, be roughly parallel to offset arm 28.One end of swing arm 32 is installed on the 3rd cantilever 24, the other end of swing arm 32 is installed with scraper bowl 34.Being arranged on the flexible of the swing arm oil hydraulic cylinder 36 between swing arm 32 and the 3rd cantilever 24 can make swing arm 32 rotate.Skew oil hydraulic cylinder 30 flexible can make that swing arm 32 and scraper bowl 34 are maintained its fore-and-aft direction position relationship and left and right moves in parallel.The flexible scraper bowl 34 that can make being arranged on the bucket hydraulic cylinder 38 between scraper bowl 34 and swing arm 32 rotates.

The rear side of the driver's seat of cockpit 16 is provided with engine compartment 40, is provided with motor in engine compartment 40 and comprises the part of oil hydraulic circuit of sealing loop forming pump driven by the engine and oil pressure pump etc.Form multiple oil pressure pumps of oil hydraulic circuit to each oil hydraulic cylinder discharge action oil as transmission device such as boom cylinder 26 grade.A pair crawler belt is driven independently of each other by left and right walking motor 42, and each walking motor 42 is hydraulic motors, supplies action oil to drive from the variable displacement oil pressure pump 48,50 (Fig. 2) forming oil hydraulic circuit.Each walking motor 42 is variable volume motors, changes its capacity and can carry out two-stage speed change.

Then the oil hydraulic circuit comprising sealing loop forming pump is described in detail with Fig. 2 to Fig. 5.As shown in Figure 2, the output shaft of motor 43 is connected to service pump 44, sealing loop forming pump namely have 3 with the multiport pump 45 of upper end-hole, be used for driving the multi-cylinder pump 46 of multiple oil hydraulic cylinder and drive a pair variable displacement oil pressure pump 48,50 of left and right running motor 42 respectively.Adopt such formation, drive each pump 44,45,46,48,50 by the driving of motor 43.

As will be explained later, multiport pump 45 is used for forming the oil hydraulic circuit of loop together with cantilever oil hydraulic cylinder 26.Bucket hydraulic cylinder 38, boom cylinder 36 and skew oil hydraulic cylinder 30 are connected on multi-cylinder pump 46 through switching valve 52,54,56 corresponding respectively.

The left and right compression chamber of each switching valve 52,54,56 is connected on the flexible switching valve 58,60,62 as switching main control valve.Each flexible switching valve 58,60,62 is connected to the discharge opening of service pump 44 through shutting down walking speedup valve loop 64, the suction port of service pump 44 is connected to outside fuel tank 66.Each flexible switching valve 58,60,62 can be switched by the corresponding operation unit being arranged on driver's seat periphery respectively.When switching each switching valve 52,54,56 by the switching of each flexible switching valve 58,60,62, elongation and the contraction of bucket hydraulic cylinder 38, boom cylinder 36 and skew oil hydraulic cylinder 30 are just switched.

Multiport pump 45 is movable ramp type variable capacity pumps, changes the direction of movable swash plate 114 (Fig. 3, Fig. 4), and cantilever oil hydraulic cylinder 26 just can be made to extend and shrink.The direction of the swash plate of multiport pump 45 can switch by the action being elevated switching valve 68, and the switching of lifting switching valve 68 can be undertaken by the operation unit such as lifting bar being arranged on driver's seat periphery.As describing in detail below, lifting switching valve 68 is arranged on multiport pump 45 integratedly, just constitutes multiport pump assembly 70.

In order to change the capacity of left and right walking motor 42, and arrange common speedup switching valve 72, through shutdown walking speedup valve loop 64, speedup switching valve 72 is connected to the discharge opening of service pump 44, speedup switching valve 72 can change the volume of walking motor 42 by two-stage.Such as, switch speedup switching valve 72, from service pump 44 to walking with the volumetric change transmission device 42a fuel feeding of motor 42, the walking volume of motor 42 just increases; Switch speedup switching valve 72, the oil in volumetric change transmission device 42a is discharged to fuel tank, the walking volume of motor 42 just reduces.According to this formation, the speed of each walking motor 42 just can be changed.Speedup switching valve 72 can be switched with the operating handle iso-variable velocity operation unit being arranged on driver's seat periphery.Walking motor 42 is connected to the discharge opening of variable displacement oil pressure pump 48,50 through advance and retreat switching valve 74.Advance and retreat switching valve 74 can switch with handover operation portions, direction such as the operating handles being arranged on driver's seat periphery, select to make the discharge opening of variable displacement oil pressure pump 48,50 and two ports of walking motor 42 which be connected.According to this formation, just can be changed by the operation in handover operation portion, direction and correspond respectively to rotating and reverse of each walking motor 42 moved forward and backward.

Make the output of each variable displacement oil pressure pump 48,50 corresponding to left and right walking motor 42 identical, vehicle is just kept straight on; Make the output of each variable displacement oil pressure pump 48,50 different, vehicle just can be turned.Although the diagram of eliminating, but the rotating motor be provided with for making cockpit 16 rotate relative to turntable 14 (Fig. 1), be connected on rotating motor through the discharge opening of switching valve by service pump, thus cockpit 16 can be made to rotate to desired direction.

Fig. 3 is the detail drawing that namely a part of loop of Fig. 2 comprises the oil hydraulic circuit of shutting down walking speedup valve loop 64 and multiport pump assembly 70.Multiport pump 45 comprises the second port 76, first port 78 and the 3rd port 80 3 ports.Second port 76 is through falling in the side pressure chamber 84 preventing from valve 82 and the first connecting port P1 to be connected to being arranged in boom cylinder 26 in the pressure chamber 84,85 of piston both sides; First port 78 falls through another and prevents valve 86 and the second connecting port P2 to be connected in the opposite side pressure chamber 85 in the pressure chamber 84,85 of the both sides of boom cylinder 26.Piston rod 88 is connected the compression face side of the piston of opposite side pressure chamber 85, and therefore, the volume of opposite side pressure chamber 85 and compression area are less than volume and the compression area of side pressure chamber 84.Such as, side pressure chamber 84 is 100: 64 with the volume ratio of opposite side pressure chamber 85.3rd port 80 is connected to the fuel tank 66 of the outside be arranged on backhoe 10 (Fig. 1) through the 3rd connecting port P3 and filter core.

Multiport pump assembly 70 comprise band lifting switching valve 68 multiport pump 45, fall prevent valve 82,86, a pair oil-filled certificated valve 90,92 and air pocket prevent valve 94.First, second, third connecting port P1, P2, P3 opening is at the outer surface of the saddle 96 (Fig. 4) of the port of formation multiport pump assembly 70.The major loop M as loop is formed by the first oil circuit S1 and the second oil circuit S2, first oil circuit S1 prevents from valve 82 to be connected to side pressure chamber 84, second oil circuit S2 falling through another from the first port 78 and prevent valve 86 to be connected to opposite side pressure chamber 85 from the second port 76 through falling.

Second port 76 of the first oil circuit S1 and fall prevent between valve 82 and first port 78 of the second oil circuit S2 and another fall and prevent between valve 86, be connected to oil-filled loop C; A pair oil-filled certificated valve 90,92 is arranged on oil-filled loop C.When becoming the first oil circuit S1 of low voltage side or the second oil circuit S2 lower than oil-filled pressure described later, the oil-filled certificated valve 90 (or 92) being low voltage side primary side is opened, and oil-filled loop C is communicated with.Between a pair oil-filled certificated valve 90,92 discharge opening of service pump 44 being connected to oil-filled loop C, therefore, multiport pump assembly 70, being connected to the 4th connecting port P4 opening of discharge opening of service pump 44 at outer surface, couples together between service pump 44 and a pair oil-filled certificated valve 90,92 of oil-filled loop C through the 4th connecting port P4.

Each oil-filled certificated valve 90,92 has high-pressure pressure-reducing valve function, and on high-tension side first oil circuit S1 or the second oil circuit S2 reaches the above high pressure of regulation, and each oil-filled certificated valve 90,92 is just unlocked; Primary side is that the oil-filled certificated valve 90 (or 92) of low voltage side is unlocked, and overbottom pressure is flow to the second oil circuit S2 or the first oil circuit S1 of low voltage side.

Air pocket prevents valve 94 from being certificated valve, the excessive variation caused in order to the instant operation etc. prevented due to the operation unit of driver's seat periphery makes the suction side of multiport pump 45 become subnormal pressure and produces air pocket, air pocket is set and prevents valve 94, in the first oil circuit S1 or the second oil circuit S2 that being used for links with described oil-filled certificated valve 90,92 can be charged to the oil subsidy from the oil storage tank 98 in multiport pump assembly 70 low pressure.

The oil circuit be connected on lifting switching valve 68 is connected to connection the 4th connecting port P4 and air pocket prevents on the oil circuit of valve 94.In the present embodiment, when being elevated switching valve 68 and part oil being supplied to a side or the opposing party of the servo hydraulic cylinder being connected to movable swash plate 114 from the discharge opening of service pump 44,3 station solenoid valves of the electrical switch operation of available driver's seat handle carry out the operation of electric oil pressure, and the oil changing multiport pump 45 freely spues direction and the oil mass that spues.

The upper solenoid electric valve preventing valve 82,86 from such as can be linked by the break-make with the enable switch such as ignition switch that falls arranged of each oil circuit S1, S2 switches, enable switch disconnects, savings does not leak to multiport pump 45 at the oil of boom cylinder 26 side, and is maintained by the effect falling the built-in check valve preventing valve 82,86.According to this formation, even if enable switch disconnects and when shelving for a long time under shut down condition, also more effectively can prevent the gravity because of cantilever 20 (Fig. 1) or car body and cause that boom cylinder 26 is unexpected to be elongated or shortened.That is, fall at leisure even if such shelving for a long time also can more effectively prevent cantilever 20 from falling at leisure or push up at scraper bowl 34 (Fig. 1) the state lower body lifting car body on the ground.

Make the 5th connecting port P5 opening that is communicated with the oil circuit being connected to the 4th connecting port P4 at the outer surface of multiport pump assembly 70, and shutdown valve assembly 100 is connected to the 5th connecting port P5 and outside fuel tank 66.Shutdown valve assembly 100 comprises the shutdown walking speedup valve loop 64 having the shutdown valve 102 be connected to by discharge opening PA on flexible switching valve 58,60,62 (Fig. 2), be connected to the walking speedup valve 104 on speedup switching valve 72 (Fig. 2) by discharge opening PB.Shutdown valve 102 can be confirmed that by the job state being such as arranged on driver's seat periphery bar switches.Such as, under the state of non-operation task state confirmation bar, shutdown valve 102 can not supply the operation oil from service pump 44 to each flexible switching valve 58,60,62.Walking speedup valve 104 is connected to the speedup switching valve 72 of Fig. 2, the same with shutdown valve 102, such as, can be confirmed bar to switch by job state.According to such formation, can more effectively prevent from only connecting enable switch simply and making vehicle to run on the contrary with the intention of driver, can more effectively prevent each portion quick actions such as bucket hydraulic cylinder 38 again.

In shutdown valve assembly 100, be provided with pressurising setting reduction valve 106, be used for the oil pressure of oil-filled loop C to be restricted to the authorized pressure preset.Reduction valve 106 also has an effect to be the action of described switching valve 52,54,56 and volumetric change transmission device 42a is installed be decided to be authorized pressure.

Next, with Fig. 4 to Fig. 9, the concrete structure as the multiport pump assembly 70 of the sealing loop forming pump of present embodiment is described.Multiport pump assembly 70 has the loop structure shown in above-mentioned Fig. 3.That is, multiport pump assembly 70 is used to the loop that formation comprises boom cylinder 26 (Fig. 3), selectively to a pair pressure chamber 84,84 discharge action oil of the piston both sides of boom cylinder 26.In following concrete structure, eliminate the diagram of the concrete structure of the lifting switching valve 68 shown in above-mentioned Fig. 3, but lifting switching valve 68 is integrally provided on the inside of multiport pump assembly 70.

As shown in Figure 4, multiport pump assembly 70 possesses shell 108, live axle 110, cylinder seat 112, movable swash plate 114 and valve plate 116, and shell 108 combination of the saddle 96 of port is fixed on outer cover body 118 and forms.That is, outer cover body 118 is combined in the one-sided of the saddle 96 of port, the inner side in the hole 120 of the inner surface (left side of Fig. 4) of inner side live axle 110 being rotatably supported in outer cover body 118 and the saddle 96 that is formed in port.The front end (left part of Fig. 4) of live axle 110 is projected into the outside of outer cover body 118, the rotating shaft of motor 43 (Fig. 3) can be attached at this front end, can transferring power.Such as, the front end of the shaft component be attached in the rotating shaft of motor 43 with live axle 110 is combined through spline, or also through gear mechanism, the front end of the rotating shaft of motor 43 and live axle 110 can be linked up, making between the two can transferring power.

Cylinder seat 112 is when the inner side of outer cover body 118 is configured in around the intermediate portion of live axle 110, being arranged on the spline fitted of peripheral part of live axle 110 in the splined hole of the central part of cylinder seat 112, this makes it possible to cylinder seat 112 is rotated together with live axle 110.Cylinder seat 112 possesses the oil hydraulic cylinder 122 being arranged on along the circumferential direction equally spaced multiple place with live axle 110 abreast; Piston 124 is inlaid in each oil hydraulic cylinder 122, can move back and forth in oil hydraulic cylinder 122.

Movable swash plate 114 is supported in outer cover body 118, its front end is circular arc, rear end is tabular surface, should be able to vert freely relative to live axle 110 during use, and withstand the piston watt being arranged on each piston 124 front end, an one side is connected to the auxiliary hydraulic cylinder (not shown) at true dip direction and the angle of inclination of changing described swash plate.Like this, outer cover body 118 and each key element be configured in inside outer cover body 118 just constitute the multiport pump 45 as variable capacity type axial piston pump.Regulate the angle of inclination of movable swash plate 114 with regard to can change the length of stroke of each piston 124, oil mass of carrying out spuing control, change the stretching speed of boom cylinder 26 (Fig. 3).Make direction reverse of verting, exhaust end and suction side just conversely, and switch step-up side and the step down side of the pressure chamber 84,85 of the both sides of boom cylinder 26 (Fig. 3).

Between cylinder seat 112 and the saddle 96 of port, be provided with valve plate 116, be fixed on the saddle 96 of port.The inner side being arranged on the oil hydraulic cylinder 122 on cylinder seat 112 communicates with the intercommunicating pore 126 of the end being formed in cylinder seat 112, the port be formed on valve plate 116, the oil circuit be formed in the saddle 96 of port; The inner side of oil hydraulic cylinder 122 can be communicated to any one port of the first connecting port P1 shown in Fig. 8, the second connecting port P2, the 3rd connecting port P3 selectively.That is, with the rotation of cylinder seat 112, each oil hydraulic cylinder 122 switches the some ports being connected to the first connecting port P1, the second connecting port P2, the 3rd connecting port P3.

As shown in Figure 5, Figure 6, the double arc groove 128,130 on the concentric circle centered by the central shaft being formed with the hole 120 to insert live axle 110 (Fig. 4) on the inner surface of outer cover body 118 of the saddle 96 of port and be arranged on the arc-shaped teat 132 in radial neutral position of each arc groove 128,130.The upper formation in circumferencial direction local of each arc groove 128,130 and arc-shaped teat 132 is radially set to the first oil groove 134 of straight line shape, makes the outer end of the first oil groove 134 (upper end of Fig. 5) lead to the primary side path 136 that described air pocket prevents valve 94.The degree of depth of the first oil groove 134 is greater than the degree of depth of each arc groove 128,130.Therefore, each arc groove 128,130 and arc-shaped teat 132 are just separated by the first oil groove 134.The circumferencial direction length of the side part (right part of Fig. 5) of the part separated by the first oil groove 134 of arc-shaped teat 132 and each arc groove 128,130 is greater than the circumferencial direction length of opposite side part (left part of Fig. 5).

The second saddle side ports 138 of section arc-shaped is formed in the side (right side of Fig. 5) of the first oil groove 134 of arc-shaped teat 132.Be formed with the first saddle side ports 140 of section arc-shaped at the opposite side (left side of Fig. 5) of the first oil groove of arc-shaped teat 132, its circumferencial direction length is less than the second saddle side ports 138.The circumferencial direction of arc-shaped teat 132 and the second saddle side ports 138 side part of each arc groove 128,130, relative with the first oil groove 134 end, is formed and radially extends the second linearly oil groove 142 equally with the first oil groove 134.The circumferencial direction of arc-shaped teat 132 and the first saddle side ports 140 side part of each arc groove 128,130, the end relative with the first oil groove 134 be formed and radially extend the 3rd linearly oil groove 144 equally with the first oil groove 134.On the inner surface of the saddle 96 of port, the second oil groove 142 around hole 120 and between the 3rd oil groove 144, be formed with the 3rd saddle side ports 146 that section is arc-shaped, its circumferencial direction length is less than the first saddle side ports 140.Each saddle side ports 138,140,146 is formed in apart from the same pitch circle of hole 120 circumference.

As shown in Figure 7, being fixed by the pin of the outer end at valve plate 116, being fixed on the inner surface of saddle 96 of port roughly combining in discoideus valve plate 116.Under this state, each oil groove 134,142,144 has the length from the outer periphery of valve plate 116 to its radially outer end end of each oil groove 134,142,144, and each oil groove 134,142,144 is communicated to the oil storage tank 98 (Fig. 4) inside outer cover body 118.As will be explained later, valve plate 116 is formed with multiple second port 76, two the first ports 78 and the 3rd port 80, through-thickness is through respectively, multiple second port 76 is formed on the same pitch circle centered by the central part of valve plate 116, two the first ports 78 are formed on this same pitch circle, and the 3rd port 80 is formed on this same pitch circle.Under state on the inner surface of saddle 96 valve plate 116 being fixed on port, each second port 76 is in the face of the second saddle side ports 138 (Fig. 6); Each first port 78 is in the face of the first saddle side ports 140 (Fig. 6); Each 3rd port 80 is in the face of the 3rd saddle side ports 146 (Fig. 6).

As shown in Figure 8, each second port 76 (Fig. 7) is connecting port, side pressure chamber, on the first oil circuit S1 that the saddle 96 being connected to port through the second saddle side ports 138 is formed.First oil circuit S1 passes through the primary side of the certificated valve 90 in a pair oil-filled certificated valve 90,92, simultaneously through falling the outer side surface of the saddle 96 preventing valve 82 at the first P1 place, connecting port arrival port.First connecting port P1 is arranged on the first outer side surface in four outer side surfaces that the peripheral portion of the saddle 96 of port is formed, and the first connecting port P1 can connect the pipe arrangement of the capacious side pressure chamber 84 (Fig. 3) leading to boom cylinder 26.

Each first port 78 (Fig. 7) is connecting port, opposite side pressure chamber, on the second oil circuit S2 that the saddle 96 being connected to port through the first saddle side ports 140 is formed.Second oil circuit S2, by the primary side of the certificated valve 92 in a pair oil-filled certificated valve 90,92, falls the second outer side surface of the saddle 96 preventing valve 86 at the second P2 place, connecting port arrival port simultaneously through another.Second connecting port P2 can connect the pipe arrangement of the little opposite side pressure chamber 85 (Fig. 3) of the volume that leads to boom cylinder 26.

3rd port 80 (Fig. 7) is fuel tank connecting port, on the 3rd oil circuit S3 that the saddle 96 being connected to port through the 3rd saddle side ports 146 is formed.3rd oil circuit S3 arrives the 3rd outer side surface of the saddle 96 of port at the 3rd P3 place, connecting port as tank port.3rd connecting port P3 can connect the pipe arrangement leading to fuel tank 66 (Fig. 3).

A part of first oil circuit S1, the second oil circuit S2 and the 3rd oil circuit S3 is that line part 148,150,152, the first connecting port P1 that extends along the roughly rectilinear direction of mutual general parallel orientation and the second connecting port P2 are respectively formed on described the one the second outer side surfaces of width direction (left and right directions of Fig. 8) both sides of the saddle 96 being positioned at port.Respectively fall that to prevent valve 82,86 to be set to its solenoid outstanding from the 4th outer side surface (upper side of Fig. 8) between described first outer side surface and the second outer side surface.The falling of inner side being configured in corresponding the first oil circuit S1 (or second oil circuit S2) is just made to prevent the path of valve 82 (or 86) from opening to solenoid energising, second port 76 is communicated to the first connecting port P1, or the first port 78 is communicated to the second connecting port P2.3rd connecting port P3 is formed on the 3rd outer side surface (downside of Fig. 8) parallel with described 4th outer side surface.In the example of fig. 8, in order to machining conveniently, allow the one end open of line part 148 of the first oil circuit S1 on the length direction another side (downside of Fig. 8) of the saddle 96 of port, this end stopper 154 blocked up.But, if take to form the method for oil circuit with mold, one end of line part 148 of the first oil circuit S1 also can be allowed not in the outer side surface upper shed of the saddle 96 of port.

As shown in Figure 4, form the intermediate portion opening of the line part 152 of the 3rd oil circuit S3 on the inner surface of the saddle 96 of port, under the state being fixed on the saddle 96 of port by outer cover body 118, the space communicated with the oil storage tank 98 inside outer cover body 118 is communicated to the 3rd oil circuit S3.

As shown in Figure 8, the oil-filled certificated valve 90,92 with relief valve function be configured in the cross walkway 163 of intersecting with described first oil circuit S1 and the second oil circuit S2 spring 157a is arranged on verify valve body 158 and be fixed on the saddle 96 of port stopper 160 between, spring 157a compose with elastic force make verification valve body 158 towards the valve seat surface of the saddle 96 of port throttle down.Be screwed in fixed component 156a on the outer end of reducing valve body 156 and be provided with spring 157b between verification valve body 158, spring 157b compose with elastic force make the head of reducing valve body 156 towards the valve seat surface of verification valve body 158 throttle down.In the oil-filled certificated valve 90 of the first oil circuit S1 side, can make reducing valve body 156 and spring 157b across space lead to the first oil circuit S1; In the oil-filled certificated valve 92 of the second oil circuit S2 side, can make reducing valve body 156 and spring 157b across space lead to the second oil circuit S2.Cross walkway 163 between a pair oil-filled certificated valve 90,92 of the saddle 96 of port is communicated with oil-filled loop oil circuit 162.In first oil circuit S1 and the second oil circuit S2 low voltage side form the verification valve body 158 of each oil-filled certificated valve 90,92 lift off a seat face and valve is opened time, oil-filled loop oil circuit 162 is just connected.Oil-filled loop oil circuit 162 is communicated to the 4th connecting port P4 being arranged on described 4th outer side surface.The pipe arrangement of the discharge opening leading to service pump 44 (Fig. 3) can be connected on the 4th connecting port P4.

As shown in Figure 5, described first outer side surface of the saddle 96 of port is provided with the 5th connecting port P5 being communicated to oil-filled loop oil circuit 162 (Fig. 8).5th connecting port P5 can be connected to the suction port of shutdown valve assembly 100 (Fig. 3) through pipe arrangement.Different from the situation of illustrated example; 4th connecting port P4 also can opening on the second outer side surface of the saddle 96 of port; the 4th connecting port P4 can be made to be communicated to the suction port of shutdown valve assembly 100 (Fig. 3), to make the 5th connecting port P5 be communicated to the discharge opening of service pump 44 (Fig. 3).

As shown in Figure 4, in oil-filled loop oil circuit 162, from length direction side (upside of Fig. 4) part of the saddle 96 of port more inclined to the cross walkway 163 being configured with oil-filled certificated valve 90,92 (Fig. 8), the branch path 164 that the thickness direction (left and right directions of Fig. 4) diverged out along the saddle 96 of port extends.The air pocket that the terminal of branch path 164 is communicated to the inner surface of the saddle 96 of port prevents primary side path 136 part of valve 94.Prevent valve 94 from imbedding in primary side path 136 air pocket, only to allow action oil to flow to branch path 164 from oil storage tank 98, as shown in Figure 7, with screw etc., baffle plate 166 is fixed on the inner surface of saddle 96 of port, across the both sides of primary side path 136, baffle plate 166 prevents valve 94 from blocking air pocket.Instant operation lifting switching valve 68 as described above, when only making the pressure of the pressure of oil-filled loop oil circuit 162 temporarily lower than the space be communicated with the oil storage tank 98 inside outer cover body 118, open air pocket and prevent valve 94, the action oil subsidy in oil storage tank 98 is charged in oil-filled loop oil circuit 162.

As shown in Figure 5 above, first oil groove 134 can be formed in second oil groove 142 of inner surface of saddle 96 of port together with the 3rd oil groove 144, the oil drained between the saddle 96 of valve plate 116 and port is turned back in outer cover body 118 (Fig. 4), can effectively prevent valve plate 116 from floating.

Then, the shape of the multiple ports 76,78,80 be formed on valve plate 116 is described in detail with Fig. 9.Valve plate 116 is being fixed on the part representative of dotted line label symbol 138,140 position being formed in the saddle side ports 138,140 on the saddle 96 of port under the state on the saddle 96 (Fig. 5 etc.) of port in Fig. 9.Valve plate 116 is made up of metal, but is different from the metal that lead alloy etc. forms the saddle 96 of port.The 3rd port 80 that valve plate 116 is formed with three the second ports 76 be communicated with the second saddle side ports 138, two the first ports 78 be communicated with the first saddle side ports 140 and is communicated with the 3rd saddle side ports 146 (Fig. 6) on same pitch circle.With the rotation of cylinder seat 112, each oil hydraulic cylinder 122 is cyclically communicated to three the second ports, 76, the 3rd port, 80, two the first ports 78.

With on the face of the side faced by the cylinder seat 112 (Fig. 4) of valve plate 116, the sense of rotation rear end being positioned at the opening end of second port 76 of rear side of cylinder seat 112 sense of rotation that the end and Fig. 9 of the opening end of the second port 76 represent with arrow α direction, the sense of rotation rear end being positioned at the opening end of first port 78 of rear side of the end of the opening end of the first port 78 and cylinder seat 112 sense of rotation (the arrow α direction of Fig. 9), in the rear end of the end of the opening end of the 3rd port 80 and sense of rotation (the arrow α direction of Fig. 9), be formed respectively as the section of breach V-shaped groove 168 roughly triangular in shape.That is, the end of the cylinder seat 112 sense of rotation homonymy of the opening end in the facing side of the oil hydraulic cylinder 122 (Fig. 4) with corresponding port is provided with multiple V-shaped groove 168.

V-shaped groove 168 from the end of the port of correspondence more to its width of front end of V-shaped groove 168 and the degree of depth less, it is just gradually little that sectional area when cutting off along the direction perpendicular to circumferencial direction gets over forward end.The shape of V-shaped groove 168 is not limited to illustrated example, as long as the shape that more forward end is just gradually little is just passable.The V-shaped groove 168 and the V-shaped groove 168 be formed on the second port 76 that are formed in the 3rd port 80 being connected to fuel tank 66 are arranged on position symmetrical centered by the center O of pitch circle, meanwhile, the same length of the length in both sides' pitch circle direction and the sense of rotation of cylinder seat 112.Therefore, the second port 76 is substantially identical with central angle θ 1, the θ 3 of circumferencial direction two ends to centre of pitch circle 0 of the V-shaped groove 168 of the 3rd port 80.With the rotation of cylinder seat 112, in piston top dead center position or piston lower dead point position one of the cylinder seat 112 sense of rotation rear end of the second port 76 and the 3rd port 80.Such as, when making action oil discharge from the side pressure chamber 84 (Fig. 3) of the boom cylinder 26 being connected to the second port 76, piston top dead center surface of position is to V-shaped groove 168 side end of the second port 76, and piston lower dead point position is in the face of V-shaped groove 168 side end of the 3rd port 80; Otherwise, when action oil supply company is received the side pressure chamber 84 of the boom cylinder 26 of the second port 76, piston lower dead point position is in the face of V-shaped groove 168 side end of the second port 76, and piston top dead center surface of position is to V-shaped groove 168 side end of the 3rd port 80.Therefore, V-shaped groove 168 side end of the first port 78 is near the centre between upper dead center position and lower dead point position.In addition, be arranged on the length of cylinder seat 112 sense of rotation of the V-shaped groove 168 on the first port 78, be less than the length of cylinder seat 112 sense of rotation of the V-shaped groove 168 be arranged on the second port 76 and the 3rd port 80.Therefore, the central angle θ 2 of circumferencial direction two ends to centre of pitch circle 0 of the V-shaped groove 168 of the first port 78 is less than central angle θ 1, the θ 3 of the second port 76 and the 3rd port 80.

In use, the boom cylinder 26 of Fig. 3 gives to piston the power in direction that namely direction to side displacement reduce or extend by deadweight and load gravity.

If adopt above-mentioned multiport pump 45, can form by the part comprising multiport pump 45 and boom cylinder 26 and close oil hydraulic circuit.Therefore, the excess oil closing oil hydraulic circuit generation is just discharged in fuel tank 66 through multiport pump 45, can reduce the loss of pipe arrangement.Possess the end of opening end of side in the face of oil hydraulic cylinder 122 of each port 76,78,80 be arranged on valve plate 116, the end of namely identical with the sense of rotation of cylinder seat 112 side and the V-shaped groove 168 gradually little towards front end.In the V-shaped groove 168 of each port 76,78,80, be arranged on the cylinder seat 112 sense of rotation length of the V-shaped groove 168 of piston top dead center position, with the cylinder seat 112 sense of rotation same length (" roughly the same " comprises identical situation, is all understood in this way in the scope of this specification and claim) of V-shaped groove 168 being arranged on piston lower dead point position.Be arranged on the cylinder seat 112 sense of rotation length of the V-shaped groove 168 of position between piston top dead center position and lower dead point position, be less than the cylinder seat 112 sense of rotation length of the V-shaped groove 168 being arranged on piston top dead center position and the V-shaped groove 168 being arranged on piston lower dead point position.Therefore, in the oil hydraulic cylinder 122 that the rotation along with cylinder seat 112 makes the action of high pressure oil flow into from the port becoming exhaust end to become exhaust end, the size of V-shaped groove 168 along with the rotation of cylinder seat 112 gradually large towards the end of port.As a result, prevent the action oil of high pressure to flow into hastily in oil hydraulic cylinder 122, alleviate the generation of air pocket, reduce pump noise and vibration.

And, the forming section of the V-shaped groove 168 near the centre being arranged on piston top dead center position and lower dead point position, with the situation of piston top dead center position with the forming section of the V-shaped groove 168 of lower dead point position be set compare, faced by the travelling speed of piston fast, the inflow velocity flowing to the action oil in oil hydraulic cylinder 122 is just high.Therefore, reduce the length of V-shaped groove 168, more restrained effectively the generation of air pocket, more effectively reduce pump noise and vibration, this is all the effect that V-shaped groove 168 is formed.As a result, as in the present embodiment, form port 76,78,80 be more than 3 multiport pump and multiport pump assembly 76 when, pump noise and vibration can be reduced.

When action oil is supplied to the side pressure chamber 84 of the boom cylinder 26 being connected to the second port 76, induction stroke is become in the oil hydraulic cylinder 122 of the 3rd port 80, piston moves to lower dead centre from upper dead center, but, the stroke speed of piston 124 from zero near the part that gradually uprises, V-shaped groove 168 is in the face of oil hydraulic cylinder 122, so the high position pressure in fuel tank 66 can not make the negative pressure in oil hydraulic cylinder 122 sharply increase, pressure change around 3rd port 80 just slowly, more effectively can suppress the generation of air pocket.V-shaped groove 168 part of the first port 78 is oil hydraulic cylinders 122 faced by the fast part of stroke of piston, even if when the formation effect of V-shaped groove 168 can not be improved, and the also deficiency of the easy function supplementary result with oil-filled loop C.

Boom cylinder 26 is given the power in the direction conjugated to side in use to piston 124 by described gravity.Therefore, the energy of the action oil that can utilize potential energy that the pressure chamber 84 (or 85) from the side forming boom cylinder 26 is ejected, be used as energy action oil being drawn into the pressure chamber 85 (or 84) of the opposing party, multiport pump 45 carries out the such action of motor, just can reduce the energy consumption of the power source such as motor 43 grade of coupled knot.

In the example shown in Fig. 9, the second port 76 one dividing into three be formed on valve plate 116, and be divided into two by the first port 78, this is the intensity in order to more effectively improve valve plate 116; If there is no the strength problem of valve plate 116, also respectively respectively can arrange one second port 76 and the first port 78, and make with the saddle side ports 138 on the saddle 96 being formed in port, 140,146 roughly the same shapes.Also each port can be separated into number beyond illustrated example.

In the example shown in Figure 10, eliminate the valve plate 116 (Fig. 9 etc.) in above-mentioned mode of execution, but directly cylinder seat 112 rotational slide is positioned on the inner surface of saddle 96 of port freely, in each saddle side ports 138,140,146 that this inner surface is formed, at the open end of the side in the face of oil hydraulic cylinder 122 (Fig. 4), formed and there is the V-shaped groove 170 with the same length of V-shaped groove 168 formed on above-mentioned valve plate 116.In this case, each saddle side ports 138,140,146 be formed on the saddle 96 of port corresponds to port.That is, the V-shaped groove 170 in the 3rd saddle side ports 146 be connected with fuel tank 66 and the cylinder seat 112 sense of rotation same length being formed in the V-shaped groove 170 in the second saddle side ports 138 is formed in.Be arranged on the cylinder seat 112 sense of rotation length of the V-shaped groove 170 in the first saddle side ports 140, be less than the cylinder seat 112 sense of rotation length of the V-shaped groove 170 be arranged in the second saddle side ports 138 and the 3rd saddle side ports 146.Other formation is the same with the formation shown in Fig. 1 to Fig. 9 with effect.When eliminating valve plate 116, in order to cylinder seat 112 be made to slip with the saddle 96 of port by the rotation of cylinder seat 112, prevent from mutually stagnating, both are preferably become by metal not of the same race.

Figure 11 is the diagram of the first case of the other example of multiple ports that the saddle of port is formed.When the configuration example shown in Figure 11, the position relationship making to be formed in the first saddle side ports 140 in the multiple saddle side ports 138,140,146 on the saddle 96 of port and the 3rd saddle side ports 146 is contrary with the formation of above-mentioned Figure 10.Thereupon, be arranged on upper dead center or the lower dead point position of piston 124 (Fig. 4) faced by the V-shaped groove 170 in the first saddle side ports 140, be arranged on the position between the upper dead center of piston 124 faced by the V-shaped groove 170 in the 3rd saddle side ports 146 and lower dead centre.Therefore, cylinder seat 112 (Fig. 4) the sense of rotation same length of the V-shaped groove 170 in the second saddle side ports 138 and the first saddle side ports 140 is arranged on; Be arranged on the cylinder seat 112 sense of rotation length of the V-shaped groove 170 in the 3rd saddle side ports 146, be less than the cylinder seat 112 sense of rotation length of the V-shaped groove 170 be arranged in the second saddle side ports 138 and the first saddle side ports 140.

When the configuration example shown in Figure 11, when action oil is supplied to the side pressure chamber 84 of the cylinder seat 26 (Fig. 3) be connected in the second saddle side ports 138, oil hydraulic cylinder 122 (Fig. 4) in the face of the 3rd saddle side ports 146 leaves upper dead center and lower dead centre is a lot of and velocity of piston is high part will in the face of V-shaped groove 170, so the pressure change of the 3rd saddle side ports 146 peripheral part increases, the effect suppressing air pocket to occur may be poorer than the situation shown in above-mentioned Fig. 9,10.; when cantilever 20 (Fig. 1) is declined or excavate time etc. the 3rd saddle side ports 146 for spuing from oil hydraulic cylinder 122; because the velocity of piston facing with the 3rd saddle side ports 146 diminishes, so the abnormal sound that the action oil easily reducing to eject from oil hydraulic cylinder 122 causes.Other formation is the same with the formation shown in Fig. 1 to Fig. 9 or Figure 10 with effect.In Figure 11, describe situation about V-shaped groove 170 being arranged in saddle side ports 138,140,146, but, when arranging valve plate 116 when the formation shown in Fig. 1 to Fig. 9, can the first port 78 be arranged on valve plate 116 be done the same with the formation situation of Figure 11 with the position relationship of the 3rd port 80 and the magnitude relationship of V-shaped groove 168, also can be contrary.In addition, when the first port 78 be arranged on the valve plate 116 of the formation shown in Fig. 1 to Fig. 9 is done the same or contrary with the formation situation of Figure 11 with the position relationship of the 3rd port 80 and the magnitude relationship of V-shaped groove 168, both can the second port 76 and the first port 78 be divided into multiple as Fig. 9, also as Figure 11, only can make one respectively.

Figure 12 is the diagram of the second case of the other example of multiple ports that the saddle of port is formed.When the configuration example shown in Figure 12, the 3rd saddle side ports be formed on the saddle 96 of port is separated into two the 3rd saddle side ports 146a, the first saddle side ports 140 is set between two the 3rd saddle side ports 146a separated.That is, the 3rd saddle side ports 146a is the separation port in two sense of rotation being separately configured in cylinder seat 112 (Fig. 4), and the sense of rotation along cylinder seat 112 is configured in two the first saddle side ports 140 and is separated between port.Like this, because the shape of two the 3rd saddle side ports 146a is symmetrical up and down relative to the imaginary plane at the inclination center of the spin axis and movable swash plate 114 (with reference to Fig. 4) that comprise pump shaft and live axle 110 (with reference to Fig. 4), so, the tilt torque of the movable swash plate 114 produced when making boom cylinder 26 (with reference to Fig. 3) extend and shrink is stablized, the lifting position of lifting switching valve 68 (with reference to Fig. 3) or the confining force of lowering position of operate mobile swash plate 114 can be reduced, and the confining force of two positions can be made substantially impartial.Thereupon, be arranged on V-shaped groove in the first saddle side ports 140 170 in the face of position between the upper dead center and lower dead centre of piston 124 (Fig. 4), than the situation of above-mentioned formation closer to the position of upper dead center side or lower dead centre side.Therefore, it is possible to prevent from being formed in each port one 38,140, V-shaped groove 170 on 146a extremely shortens, and easily can guarantee the accuracy to shape of each V-shaped groove 170.Other formation is the same with the formation shown in above-mentioned Figure 10 or Fig. 1 to Fig. 9 with effect.In Figure 12, describe V-shaped groove 170 be arranged on saddle side ports 138,140, situation on 146a, but, formation shown in Fig. 1 to Fig. 9 arranges valve plate 116 like that, the same with the formation of Figure 12, also the 3rd port be arranged on valve plate 116 can be separated into two, and the first port 78 be configured between two the 3rd ports separating.

Although the diagram of eliminating, but, in the configuration example of Figure 12, also the first port in the multiple ports be formed on the saddle 96 of valve plate 116 or port or the first saddle side ports can be separated into two, and the 3rd port or the 3rd saddle side ports be arranged on separate between two the first ports or the first saddle side ports.That is, the first port also can make the separation port in two sense of rotation being separately configured in cylinder seat 112, and the 3rd port arrangement between two separation ports of the sense of rotation of cylinder seat 112.

In the loop of above-mentioned Fig. 3, multiport pump assembly 70 and shutdown valve assembly 100 are made the component of mutual split.But; also can as on Figure 13 as shown in the first case loop of other examples; shutdown valve assembly 100 is wholely set in multiport pump assembly 70, is made of one assembly, so also can omit the pipe arrangement connecting multiport pump assembly 70 and shutdown valve assembly 100.In the loop of Figure 13, the inside of multiport pump assembly 70 is provided with reduction valve 106a, prevents valve 94 to be connected in parallel with air pocket.Reduction valve 106a has the function same with the pressurising setting reduction valve 106 on the shutdown valve assembly 100 being arranged on Fig. 3.In the loop of Figure 13, other formation is the same with the situation in the loop of Fig. 3 with effect.

The loop of the second case of other example as shown in figure 14, also can be connected to the 3rd connecting port P3 of multiport pump assembly 70 from connecting branch path 172 that the suction port of service pump 44 and the oil circuit of fuel tank 66 diverge out.When this formation, owing to the action oil of being discharged by the 3rd connecting port P3 from the 3rd port 80 being delivered to service pump 44 side along Figure 14 with the direction that arrow β represents along with reducing of boom cylinder 26, so reduce the driving force of the motor 43 for driving service pump 44, be more prone to save the energy.In the loop of Figure 14, other formation is the same with the situation in the loop of Fig. 3 with effect.

Figure 15 is the schematic partial sectional view of the multiport pump assembly of other examples of embodiments of the present invention.Figure 16 is the view from seeing to the right from the left side of Figure 15 after Figure 15 takes out valve plate.Figure 17 is the D-D sectional view of Figure 15.In the formation situation of other examples shown in Figure 15 to Figure 17, instead of in the formation shown in above-mentioned Fig. 4 to Fig. 9 and plane valve plate 116 (with reference to Fig. 4, Fig. 5, Fig. 9) is made in thickness direction both sides, the valve plate 176 used has towards sphere portion 174 protruding outside at one of them mask of thickness direction, and another face of thickness direction is made plane.Valve plate 176 is under the state preventing the skew of in-plane with the pin 180 (Figure 17) be supported on the saddle 96 of port, and hold under the arm between cylinder seat 112 and the saddle 96 of port, valve plate 176 is supported on cylinder seat 112.

As shown in figure 16, valve plate 176 is formed with the second port 76 be communicated with the second saddle side ports 138 (Figure 17), the first port 78 be communicated with the first saddle side ports 140 (Figure 17) and is arranged on two the 3rd ports 80 of the first port 78 both sides along the circumferencial direction of pitch circle on same pitch circle.Each 3rd port 80 leads to a side or the opposing party of two the 3rd saddle side ports 146 (Figure 17).Each 3rd saddle side ports 146 is all communicated to the 3rd oil circuit S3 communicated with oil storage tank 98 and fuel tank 66 (with reference to Fig. 3).Along with the rotation of cylinder seat 112 (Figure 15), each oil hydraulic cylinder 122 (Figure 15) sequential communication, to the second port 76, the 3rd port 80, first port 78, another the 3rd port 80, carries out repeatedly.

At valve plate 176 on the face of the side of cylinder seat 112 (Figure 15), sense of rotation rear end, above-mentioned sense of rotation (the arrow α direction of Figure 16) rear end at the opening end of each the 3rd port 80, above-mentioned sense of rotation (the arrow α direction of Figure 16) rear end at the opening end of the first port 78 of the cylinder seat 112 represented with arrow α direction in Figure 16 of the opening end of the second port 76, be formed respectively as the section of breach V-shaped groove 168 roughly triangular in shape.

Be formed in the V-shaped groove 168 on the 3rd port 80 of the downside of the Figure 16 in two the 3rd ports 80 being connected to fuel tank 66 (with reference to Fig. 3), the position of the center O symmetry about pitch circle is arranged on the V-shaped groove 168 be formed on the second port 76, meanwhile, the cylinder seat 112 sense of rotation length of the V-shaped groove 168 of the 3rd port 80 and the V-shaped groove of the second port 76 is slightly same.Be formed in the cylinder seat 112 sense of rotation length of the V-shaped groove 168 on the 3rd port 80 of the upside of Figure 16, be less than the sense of rotation length of the 3rd port 80 of downside and the V-shaped groove 168 of the second port 76.In addition, be formed in the cylinder seat 112 sense of rotation length of the V-shaped groove 168 on the first port 78, be less than the sense of rotation length of other V-shaped grooves 168.Therefore, the central angle θ 2 of circumferencial direction two ends to centre of pitch circle O of the V-shaped groove 168 of the first port 78 is less than central angle θ 1, θ 3, the θ 3 ' of other V-shaped grooves 168.

The effect of this formation is the same substantially with the situation of the formation of above-mentioned Figure 12.Namely, two the 3rd saddle side ports 146 are relative to the upper and lower almost symmetry of imaginary plane at the inclination center of the spin axis and movable swash plate 114 (Figure 15) that comprise live axle 110 (Figure 15), so, the tilt torque of the movable swash plate 114 produced when making boom cylinder 26 (with reference to Fig. 3) extend and shrink is stablized, can reduce the lifting position of lifting switching valve 68 (with reference to Fig. 3) or the confining force of lowering position of operate mobile swash plate 114, and the confining force that two orientation can be made to put is substantially impartial.Be arranged on the position of V-shaped groove 168 close upper dead center side or the lower dead centre side faced by position between the upper dead center and lower dead centre of piston 124 (Figure 15) on the first port 78.Therefore, it is possible to prevent the V-shaped groove 168 be formed on each port 76,78,80 from extremely shortening, the accuracy to shape of each V-shaped groove 168 easily can be guaranteed.

In addition, when the formation of Figure 15 to Figure 17, valve plate 176 has towards sphere portion 174 protruding outside at one of them mask of thickness direction.Thereupon, in the end of cylinder seat 112, inwards recessed sphere portion 178 is arranged on the face facing to the sphere portion 174 of valve plate 176.The sphere portion 178 of cylinder seat 112 is with sphere portion 174 close contact of valve plate 176 and slide relative to it.Therefore, compared with the situation of the contact between plane, the area of contact between mutually sliding sphere portion 174,178 is larger, from the leakage of oil between sphere portion 174,178 just seldom.The face pressure acted between sphere portion 174,178 is just little, and the wearing and tearing between each sphere portion 174,178 are just few.Other formation is the same with the formation shown in above-mentioned Fig. 1 to Fig. 9 with effect.

In the formation of Figure 15 to Figure 17, the same with Fig. 9, also can the second port 76 be separated into multiple.Also in the upside of Figure 16, Figure 17 or downside, two the 3rd ports 80 can be concentrated is one, and thereupon, also in the upside of Figure 16, Figure 17 or downside, two the 3rd saddle side ports 146 can be concentrated is one.

Claims (2)

1. one kind is used for forming the loop that comprises oil hydraulic actuator and selectively to the sealing loop forming pump of a pair pressure chamber's discharge action oil of the piston both sides of oil hydraulic actuator; It is characterized in that:

Possess shell, rotatably configure in the enclosure and be provided with multiple oil hydraulic cylinder cylinder seat, be reciprocally separately positioned on the multiple pistons in multiple oil hydraulic cylinder, the movable swash plate that each piston can be moved back and forth in each oil hydraulic cylinder with the rotation of cylinder seat movably and be formed in the multiple ports of more than 3 on shell or fixing other components in the enclosure;

Multiple port comprise the side being connected to a pair pressure chamber connecting port, side pressure chamber, be connected to the connecting port, opposite side pressure chamber of the opposite side of a pair pressure chamber and be connected to the fuel tank connecting port of fuel tank;

Each oil hydraulic cylinder can be communicated on each port with the rotation of cylinder seat selectively;

Multiple port also possesses the end of side opening end in the face of oil hydraulic cylinder and the end of cylinder seat sense of rotation homonymy and the otch gradually little towards front end that are arranged on each port;

Be arranged in the otch that between piston top dead center position and lower dead point position, position is relative with oil hydraulic cylinder, be arranged on the cylinder seat sense of rotation length of the otch of connecting port, opposite side pressure chamber, be less than the cylinder seat sense of rotation length of the otch being arranged on piston top dead center position and the otch being arranged on piston lower dead point position

And, be arranged in the otch that between piston top dead center position and lower dead point position, position is relative with oil hydraulic cylinder, be arranged on the cylinder seat sense of rotation length of the otch of connecting port, opposite side pressure chamber, be less than and be arranged on piston top dead center position or be arranged on the cylinder seat sense of rotation length being arranged on the otch of connecting port, side pressure chamber in the piston lower dead point position place otch relative with oil hydraulic cylinder

Fuel tank connecting port is separated into the separation port of two;

Connecting port, side pressure chamber is configured with between two separation ports of the sense of rotation of cylinder seat.。

2. sealing loop forming pump according to claim 1, is characterized in that,

Be arranged on two sides be separated in port and be separated otch on port, from position be positioned at the position different with the piston relative position of the otch being arranged on connecting port, side pressure chamber, piston lower dead point position is relative with oil hydraulic cylinder with upper dead center position place.