JP7341884B2 - Variable displacement hydraulic rotating machine - Google Patents

Description

The present disclosure relates to a variable displacement hydraulic rotating machine that is mounted on a construction machine such as a hydraulic excavator and used as a variable displacement hydraulic pump or a hydraulic motor.

In general, a variable displacement hydraulic rotating machine includes a tilting actuator in which a servo piston is movably inserted into a cylinder hole in order to tilt a variable displacement part such as a swash plate or a valve plate, and a tilting actuator. a regulator that drives the servo piston; a hydraulic pressure passage that connects the regulator to a hydraulic chamber formed between one end of the servo piston and the cylinder hole; and a hydraulic pressure passage that connects the regulator to the other end of the servo piston and the cylinder. Another hydraulic pressure passage connecting the regulator and another hydraulic pressure chamber formed between the hole and the regulator is provided.

In addition, the regulator includes a regulator casing provided with a cylindrical hole, and a control sleeve provided inside the regulator casing so as to be relatively displaceable, and tiltable to operate a servo piston in each hydraulic pressure chamber through a hydraulic pressure passage. A spool for supplying and discharging control pressure, a feedback link located between the servo piston and the control sleeve to transmit the displacement of the servo piston to the control sleeve, and a feedback link located on one side of the spool for moving the spool in the other direction. The pilot pressure chamber includes one pilot pressure chamber provided in the regulator casing and another pilot pressure chamber located on the other side of the spool and provided in the regulator casing to move the spool in one direction. (Patent Document 1).

In a variable displacement hydraulic rotary machine configured in this way, for example, when pilot pressure is supplied to one pilot pressure chamber, the spool moves in the other direction within the control sleeve, discharging pressure oil from the pump. The other hydraulic pressure chambers of the tilting actuator are supplied through other hydraulic pressure passages. As a result, the servo piston moves in one direction, and the variable capacity section tilts the swash plate or the like to the commanded angle. The feedback link also causes the control sleeve to move in the other direction during movement of the servo piston.

JP2017-036713A

By the way, in the above-mentioned Patent Document 1, the spool is moved only by the pilot pressure supplied to the pilot pressure chamber. Due to the structure of mechanical feedback, there is a problem in that when the servo piston approaches the target position, it takes time to reach the target position due to the influence of the servo piston's movement speed reduction section.

An object of an embodiment of the present invention is to provide a variable displacement hydraulic rotating machine that can move a servo piston to a target position in a short time.

One embodiment of the present invention includes a tilting actuator in which a servo piston is movably inserted into a cylinder hole in order to tilt a variable capacity part, and a regulator that drives the servo piston of the tilting actuator. one hydraulic pressure passage connecting one hydraulic pressure chamber formed between one end of the servo piston and the cylinder hole and the regulator, and the other end of the servo piston and the cylinder hole; another hydraulic passage connecting the regulator with another hydraulic chamber formed in the regulator, the regulator having a regulator casing provided with a cylindrical hole and a control sleeve disposed within the regulator casing. a spool that is provided so as to be relatively displaceable and that supplies and discharges tilting control pressure for operating the servo piston to and from each of the hydraulic pressure chambers through the hydraulic pressure passage; and a spool that is provided between the servo piston and the control sleeve. a feedback link conveying the displacement of the servo piston to the control sleeve; and a pilot pressure chamber located on one side of the spool and provided in the regulator casing for moving the spool in the other direction. and another pilot pressure chamber located on the other side of the spool and provided in the regulator casing for operating the spool in one direction, the variable displacement hydraulic rotating machine comprising: The regulator casing includes one auxiliary pressure chamber, which is located on one side of the spool and is independent of the one pilot pressure chamber, for moving the spool in one direction. further comprising another auxiliary pressure chamber located on the other side of the spool and independent of the other pilot pressure chamber, and connecting the one auxiliary pressure chamber and the other hydraulic pressure passage. A first auxiliary passage connecting the hydraulic pressure passage and a second auxiliary passage connecting the other auxiliary pressure chamber and the first hydraulic pressure passage are provided.

According to one embodiment of the present invention, the servo piston can be moved to the target position in a short time.

1 is a sectional view showing a variable displacement swash plate type hydraulic pump according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the swash plate type hydraulic pump of FIG. 1 viewed from the direction of arrow II-II. FIG. 2 is a cross-sectional view showing a tilting actuator, a regulator, and the like. FIG. 4 is a cross-sectional view seen from the same position as FIG. 3, showing a state where the spool is moved in another direction to supply pressure oil to another hydraulic pressure chamber of the tilting actuator. FIG. 4 is a cross-sectional view of the spool seen from the same position as FIG. 3 with the spool moved in another direction. FIG. 4 is a cross-sectional view of the tilting actuator in a state where the servo piston has moved in one direction, viewed from the same position as FIG. 3; FIG. 4 is a sectional view of the spool moved in one direction, viewed from the same position as FIG. 3; FIG. 3 is a characteristic diagram showing the relationship between target tilt angle and time. FIG. 4 is a cross-sectional view of a regulator according to a second embodiment viewed from the same position as FIG. 3 together with a tilting actuator and the like. FIG. 10 is a front view showing the one side stepped piston shown in FIG. 9 alone.

Hereinafter, as a variable displacement hydraulic rotating machine according to an embodiment of the present invention, a variable displacement swash plate type hydraulic pump (in particular, the swash plate is tilted in both one direction and the other direction from a neutral position with a tilt angle of 0 degrees) will be described. The present invention will be described in detail with reference to the accompanying drawings, taking as an example a double tilting type hydraulic pump that can be driven in rotation.

1 to 8 show a first embodiment of the invention. In FIG. 1, a variable displacement swash plate type hydraulic pump 1 (hereinafter referred to as hydraulic pump 1) as a variable displacement hydraulic rotary machine has a casing 2 forming an outer shell. The casing 2 has a stepped cylindrical casing main body 3 whose proximal end, which is the side facing a prime mover (not shown) such as an engine, is a front bottom portion 3A, and a stepped cylindrical casing main body 3 with a front bottom portion 3A formed on the casing main body 3 so as to close the distal end side of the casing main body 3. A rear casing 4 is provided. In the rear casing 4 of the casing 2, supply and discharge passages 15A, 15B, etc., which will be described later, are formed.

The casing body 3 of the casing 2 is provided with an actuator mounting portion 3B at a position spaced apart from the front bottom portion 3A in the axial direction. The actuator mounting portion 3B is provided so as to protrude outward in the radial direction of the casing body 3, and a tilting actuator 16, which will be described later, is provided inside. For example, a rectangular opening 3C is formed in the actuator mounting portion 3B between the actuator mounting portion 3B and a regulator 21, which will be described later. A feedback link 31, which will be described later, is movably inserted into this opening 3C.

A rotary shaft 5 is rotatably provided within the casing 2 . The rotating shaft 5 is rotatably attached to the front bottom portion 3A of the casing body 3 and the rear casing 4 via bearings or the like. An output shaft (not shown) of a prime mover such as an engine or a motor is connected to the protruding end side of the rotary shaft 5 that protrudes in the axial direction from the front bottom portion 3A, and the rotary shaft 5 is rotationally driven by the prime mover.

The cylinder block 6 is located inside the casing 2 and provided on the outer peripheral side of the rotating shaft 5. The cylinder block 6 is spline-coupled to the rotating shaft 5 and is rotationally driven together with the rotating shaft 5. The cylinder block 6 is provided with a plurality of axially extending cylinders 7 spaced apart in the circumferential direction, for example nine cylinders (see FIG. 2). A piston 8 is slidably inserted into each cylinder 7 . Each piston 8 reciprocates within the cylinder 7 by rotation of the cylinder block 6, sucks hydraulic oil into each cylinder 7 from the valve plate 14 side, which will be described later, and discharges it as high-pressure oil.

In this case, each piston 8 reciprocates between a bottom dead center position where it protrudes (extends) from the cylinder 7 in the axial direction and a top dead center position where it enters (shrinks) into the cylinder 7. During one rotation of the cylinder block 6, each piston 8 undergoes a suction stroke in which it slides inside the cylinder 7 from the top dead center to the bottom dead center, and a sliding stroke from the bottom dead center toward the top dead center. Repeat the discharge stroke.

During the suction stroke of the piston 8, which corresponds to half a rotation of the cylinder block 6, hydraulic oil is sucked into the cylinder 7 from one side of supply and discharge passages 15A and 15B, which will be described later. In addition, in the discharge stroke of the piston 8 corresponding to the remaining half rotation of the cylinder block 6, the piston 8 turns the oil in the cylinder 7 into high-pressure oil and discharges it from the other side of the supply and discharge passages 15A and 15B, which will be described later. Exhale inward.

As shown in FIG. 1, a shoe 9 is swingably provided at the protruding end of each piston 8. Each shoe 9 is pressed against a smooth surface 11A of a swash plate 11, which will be described later, by a pressing force (hydraulic force) from the piston 8. Each shoe 9 rotates together with the rotating shaft 5, cylinder block 6, and piston 8 while being pressed against the smooth surface 11A, thereby sliding on the smooth surface 11A so as to draw a circular trajectory.

A swash plate support 10 is fixedly provided on the front bottom portion 3A of the casing body 3. The swash plate support 10 is disposed around the rotating shaft 5 on the back side of the swash plate 11. A pair of tilting sliding surfaces 10A that tiltably support the swash plate 11 are formed on the swash plate support 10 as concave curved surfaces (not shown). The pair of tilting sliding surfaces 10A are spaced apart from each other in the radial direction of the rotating shaft 5.

The swash plate 11 is provided in the casing 2 so as to be tiltable. The swash plate 11 is attached to the front bottom 3A side of the casing body 3 via the swash plate support 10, and has a smooth surface 11A serving as a sliding surface. Further, an insertion hole 11B is formed in the center of the swash plate 11, through which the rotating shaft 5 is inserted with a gap. Further, on the back side of the swash plate 11, a pair of leg portions 11C are provided which are spaced apart from each other with the insertion hole 11B in between. Each leg 11C is tiltably abutted on each tilting sliding surface 10A of the swash plate support 10.

Here, the swash plate 11 is tiltably supported by each tilting sliding surface 10A of the swash plate support 10 via each leg 11C, and in this state is tilted and driven by a tilting actuator 16, which will be described later. Ru. The swash plate 11 constitutes a part of a variable capacity section that changes the discharge capacity of the hydraulic pump 1 according to the tilt angle. The tilt actuator 16 tilts the swash plate 11 from a position where the tilt angle is 0 degrees in both one direction and the other direction (arrow A direction and arrow B direction shown in FIG. The discharge direction can be switched as appropriate so as to be reversed.

The tilting lever 12 is integrally provided on the side of the swash plate 11. The tilting lever 12 extends from the side of the swash plate 11 toward a servo piston 19, which will be described later. An engagement pin 12A is provided on the tip side of the tilting lever 12, and a servo piston 19, which will be described later, is connected to the engagement pin 12A via a slide plate 13.

The slide plate 13 is slidably inserted into a slide groove 19D of a servo piston 19, which will be described later. The slide plate 13 is formed as a substantially rectangular plate, and slides (slidingly displaces) in a direction across the servo piston 19 within the slide groove 19D. A fitting hole 13A is formed in the center of the slide plate 13, into which the engagement pin 12A of the tilting lever 12 is rotatably inserted. That is, the slide plate 13 is attached to the slide groove 19D of the servo piston 19 with the engagement pin 12A of the tilting lever 12 inserted into the fitting hole 13A in advance. The slide plate 13 transmits the axial displacement of the servo piston 19 to the swash plate 11 via the tilting lever 12, so that the swash plate 11 follows the servo piston 19 in the direction of arrow A and the direction of arrow B. It is tilted and rotated in the direction.

The valve plate 14 is fixedly provided to the rear casing 4. The valve plate 14 constitutes a switching valve plate that comes into sliding contact with the end surface of the cylinder block 6. For this reason, the valve plate 14 is formed with a pair of supply and discharge ports 14A and 14B that are shaped like eyebrows and extend around the rotating shaft 5. These supply/discharge ports 14A, 14B are switched to either a suction port or a discharge port depending on the direction in which the swash plate 11 is tilted. For example, when the supply/discharge port 14A becomes a low-pressure suction port, the supply/discharge port 14B becomes a high-pressure discharge port. On the other hand, when the tilting direction of the swash plate 11 is reversed, the supply/discharge port 14A becomes a high-pressure discharge port, and the supply/discharge port 14B becomes a low-pressure suction port.

A pair of supply and discharge passages 15A and 15B formed in the rear casing 4 are passages through which hydraulic oil is sucked in and discharged. These supply and discharge passages 15A and 15B supply and discharge hydraulic oil (pressure oil) into the cylinder 7 via the valve plate 14. Here, when the rotating shaft 5 is rotationally driven within the casing 2, the pistons 8 reciprocate within each cylinder 7 as the cylinder block 6 rotates, and these pistons 8 move from one side of the supply/discharge passages 15A and 15B. While sucking hydraulic oil into the cylinder 7, pressure oil is discharged to the other side of the supply/discharge passages 15A and 15B.

The tilting actuator 16 is provided within the actuator mounting portion 3B of the casing body 3. As shown in FIGS. 2 and 3, the tilting actuator 16 is installed in cylinder holes 17A and 17B located on the outside of the cylinder block 6 in the radial direction and formed in the actuator mounting portion 3B, and in each cylinder hole 17A and 17B. The servo piston 19 is movably inserted and fitted over the servo piston 19. The tilting actuator 16 drives the swash plate 11 to tilt in both one direction and the other direction (arrow A direction and arrow B direction in FIG. 2) from a position where the tilt angle is 0 degrees by a servo piston 19. do. An axially outer opening of the cylinder hole 17A is closed by a lid 18A. Further, the axially outer opening of the cylinder hole 17B is closed by a lid 18B.

The servo piston 19 is formed, for example, as a cylindrical body (or a cylindrical body provided with a partition inside). The servo piston 19 has one axial end 19A slidably fitted into the cylinder hole 17A, and the other axial end 19B slidably fitted into the cylinder hole 17B. . The one end portion 19A and the other end portion 19B have the same diameter (the same diameter).

Furthermore, a link mounting groove 19C and a slide groove 19D are recessed in the axially (lengthwise) middle of the servo piston 19 at positions facing each other in the radial direction (up and down in FIG. 2). A tip 31B of a feedback link 31, which will be described later, is pivotally engaged with a link attachment groove 19C of the servo piston 19. The engagement pin 12A of the tilting lever 12 is engaged with the slide groove 19D of the servo piston 19 via the slide plate 13.

As shown in FIGS. 2 and 3, the link mounting groove 19C has a U-shaped cross section and is formed by cutting a part of the outer circumferential side of the servo piston 19 in the tangential direction (direction perpendicular to the axial direction). Consists of grooves. When the tip 31B of the feedback link 31 engages with the link attachment groove 19C, the tip 31B of the feedback link 31 moves in the axial direction together with the servo piston 19.

The slide groove 19D is provided on the opposite side in the radial direction from the link mounting groove 19C across the axis of the servo piston 19. The slide groove 19D is a notch groove with a U-shaped cross section formed by cutting out a part of the outer peripheral side of the servo piston 19 in the tangential direction (direction perpendicular to the axial direction). The engagement pin 12A of the tilting lever 12 is engaged with the slide groove 19D via the slide plate 13.

One hydraulic chamber 20A is formed as an oil chamber between one end 19A of the servo piston 19 and the cylinder hole 17A (lid 18A). One hydraulic pressure chamber 20A is connected to one side actuator port 23F of the case body 23 through one hydraulic pressure passage 42, which will be described later.

The other hydraulic pressure chamber 20B is formed as an oil chamber between the other end 19B of the servo piston 19 and the cylinder hole 17B (lid 18B). The other hydraulic pressure chamber 20B is connected to the other side actuator port 23G of the case body 23 through another hydraulic pressure passage 43, which will be described later.

The tilting actuator 16 supplies and discharges tilting control pressure to one hydraulic pressure chamber 20A through one hydraulic pressure passage 42, and supplies and discharges tilting control pressure to another hydraulic pressure chamber 20B through another hydraulic pressure passage 43. do. Thereby, the tilting actuator 16 slides and displaces the servo piston 19 in the axial direction of the cylinder holes 17A, 17B according to the tilting control pressure supplied to and discharged from each hydraulic pressure chamber 20A, 20B. Further, the axial displacement of the servo piston 19 is transmitted to the swash plate 11 via the slide plate 13 and the tilting lever 12, so that the swash plate 11 follows the servo piston 19 in the direction of arrow A. Alternatively, it is tilted and driven in the direction of arrow B.

Next, the configuration and control operation of the regulator 21, which are the features of this embodiment, will be described in detail.

The regulator 21 is configured as a hydraulic servo valve that supplies and discharges tilting control pressure to the tilting actuator 16. Regulator 21 drives servo piston 19 of tilting actuator 16 . As shown in FIG. 3, the regulator 21 includes a regulator casing 22, a control sleeve 26, a spool 27, a feedback link 31, one pilot pressure chamber 35, another pilot pressure chamber 37, one auxiliary pressure chamber 39, and another auxiliary pressure chamber 35. It is configured to include a pressure chamber 41.

As shown in FIG. 1, the regulator casing 22 is provided on the side of the actuator mounting portion 3B of the casing body 3. The regulator casing 22 is disposed so as to cover an opening 3C provided in the actuator mounting portion 3B of the casing body 3 from the outside. Thereby, the inside of the regulator casing 22 communicates with the inside of the actuator mounting portion 3B of the casing body 3 via the opening 3C.

The regulator casing 22 includes a cylindrical case body 23 extending in the axial direction of the servo piston 19 (left-right direction in FIGS. 2 and 3), and a cylindrical case body 23 extending in the axial direction of the servo piston 19 (left side in FIGS. 2 and 3). The housing includes a block 24 on one side provided thereon and a block 25 on the other side provided on the other side of the case body 23 in the axial direction (the right side in FIGS. 2 and 3).

Inside the case body 23, one side from the axial middle part is a sleeve sliding part 23A as a cylindrical hole, and the other side from the other end of the sleeve sliding part 23A is a spring accommodating part 23B having a larger diameter than the sleeve sliding part 23A. Furthermore, the other side from the other end of the spring accommodating part 23B is a spring receiving accommodating part 23C having a larger diameter than the spring accommodating part 23B. A stepped portion 23D is formed between the sleeve sliding portion 23A and the spring accommodating portion 23B.

A control sleeve 26, which will be described later, is fitted into the sleeve sliding portion 23A so as to be movable in the axial direction. Further, a spring member 29 is housed in the spring housing portion 23B, located between the stepped portion 23D and a spring receiver 30, which will be described later. Furthermore, a cylindrical spring receiver 30 is accommodated in the spring receiver housing portion 23C. The other side common piston 33, which will be described later, slides on the inner circumferential surface of the spring receiver 30.

A pump port 23E is provided in the case body 23 so as to communicate with an axially intermediate portion of the sleeve sliding portion 23A. Further, the case body 23 is provided with an actuator port 23F on one side and an actuator port 23G on the other side at positions sandwiching the pump port 23E. Each actuator port 23F, 23G communicates with the sleeve sliding portion 23A similarly to the pump port 23E.

On the other hand, a drain passage 23H is formed in the case body 23 by communicating one side of the sleeve sliding portion 23A and the spring housing portion 23B. This drain passage 23H is located on one side of a control sleeve 26, which will be described later, and opens into a sleeve sliding portion 23A. Thereby, the drain passage 23H allows the hydraulic oil returned to the one-side actuator port 23F to flow into the casing main body 3 communicating with it via the spring accommodating portion 23B.

Further, the case body 23 is provided with a link insertion hole 23J located on the other side of the sleeve sliding portion 23A. For example, the link insertion port 23J is a part of the opening 3C of the casing body 3, and allows the feedback link 31 (described later) to be inserted therethrough in an operable manner, and the inside of the case body 23 is inserted into the casing body 3 via the actuator mounting portion 3B. Connected.

The one side block 24 closes one side of the sleeve sliding portion 23A. The one side block 24 is provided with a main small-diameter cylinder 24A and a sub-small-diameter cylinder 24B that are open at the end face on the case body 23 side. Each small-diameter cylinder 24A, 24B is formed as a small-diameter bottomed hole extending parallel to the axis of the sleeve sliding portion 23A (the axis of the spool 27) at a position that fits within the diameter dimension of the sleeve sliding portion 23A. The small diameter cylinders 24A, 24B are arranged in a radial direction perpendicular to the axis of the spool 27, that is, in the radial direction of the sleeve sliding portion 23A.

Further, the one side block 24 is provided with a pilot port 24C communicating with the main small diameter cylinder 24A, and an auxiliary port 24D communicating with the sub small diameter cylinder 24B. The pilot port 24C is connected to one tilt operation valve (none of which is shown) via a pilot pipe. The auxiliary port 24D is connected to another hydraulic pressure passage 43 via a first auxiliary passage 44, which will be described later.

On the other hand, the other side block 25 closes the other side of the spring receiver accommodating part 23C, and fixes a spring receiver 30, which will be described later, in the spring receiver accommodating part 23C. The other side block 25, like the one side block 24, is provided with a main small diameter cylinder 25A, a sub small diameter cylinder 25B, a pilot port 25C, and an auxiliary port 25D. The pilot port 25C is connected to other tilt operation valves (none of which are shown) via a pilot pipe. The auxiliary port 25D is connected to one hydraulic pressure passage 42 via a second auxiliary passage 45, which will be described later.

The control sleeve 26 is fitted into the sleeve sliding portion 23A of the case body 23 so as to be displaceable in the axial direction. The control sleeve 26 is formed as a cylindrical body, and its outer peripheral surface is in oil-tight sliding contact with the sleeve sliding portion 23A. Further, the inner peripheral side of the control sleeve 26 is a spool sliding hole 26A in which a spool 27, which will be described later, slides in an oil-tight manner. The control sleeve 26 has three sets of oil holes 26B, 26C, and 26D passing through it in the radial direction. The oil holes 26B, 26C, and 26D are arranged at intervals from one side to the other in the order of oil hole 26C, oil hole 26B, and oil hole 26D.

The oil hole 26B located in the middle is always in communication with the pump port 23E of the case body 23 and is separated from each actuator port 23F, 23G. The oil hole 26C located on one side is always in communication with the one side actuator port 23F of the case body 23. Moreover, the oil hole 26D located on the other side is always in communication with the other side actuator port 23G of the case body 23.

The control sleeve 26 is provided with a link engagement groove 26E located at the other end. The link engagement groove 26E is formed by notching in the tangential direction, and is engaged with a pin member 31A of the feedback link 31, which will be described later.

The spool 27 of the regulator 21 is provided in the regulator casing 22, that is, in the sleeve sliding portion 23A of the case body 23 via a control sleeve 26 so as to be relatively displaceable. The spool 27 supplies and discharges a tilting control pressure for operating the servo piston 19 to and from the respective hydraulic pressure chambers 20A and 20B through the respective hydraulic pressure passages 42 and 43. The spool 27 is formed as a stepped cylinder that is longer than the control sleeve 26 . The spool 27 is slidably inserted into the spool sliding hole 26A of the control sleeve 26. In this state, the spool 27 is displaced toward the other side (in the direction of arrow B) as the end surface 27A of one side is pushed by the one side common piston 32 (first main piston 34, first sub-piston 38) described below. However, the other side end surface 27B is displaced to one side (in the direction of arrow A) by being pushed by the other side common piston 33 (second main piston 36, second sub-piston 40), which will be described later.

Flange-shaped lands 27C and 27D are provided on the outer peripheral side of the spool 27. The land 27C is arranged on one side of the spool 27 in the length direction and corresponds to the oil hole 26C of the control sleeve 26. The land 27D is arranged near the middle of the spool 27 in the length direction, and corresponds to the oil hole 26D of the control sleeve 26. Further, the width dimension of each land 27C, 27D is set to be equal to the hole diameter of the oil hole 26C, 26D.

Here, as shown in FIG. 3, when the spool 27 is in the neutral position, the lands 27C and 27D of the spool 27 block the oil holes 26C and 26D of the control sleeve 26 from the inner spool sliding hole 26A. ing. In addition, the lands 27C and 27D of the spool 27 are arranged when the spool 27 is displaced from the neutral position to the other side in the axial direction (in the direction of arrow B) within the spool sliding hole 26A, as shown in FIGS. 4 and 5, for example. Sometimes, the land 27C moves to the other side than the oil hole 26C of the control sleeve 26, and the land 27D moves to the other side than the oil hole 26D. Thereby, the oil hole 26D communicates with the oil hole 26B through the spool sliding hole 26A. On the other hand, when the spool 27 is displaced from the neutral position to one side in the axial direction within the spool sliding hole 26A, the lands 27C and 27D of the spool 27 move to one side of the oil hole 26C of the control sleeve 26. However, the land 27D moves to one side of the oil hole 26D. Thereby, the oil hole 26C communicates with the oil hole 26B through the spool sliding hole 26A.

An annular convex portion 27E is provided on the outer circumferential side of the spool 27, located on the other side in the length direction. This annular convex portion 27E constitutes a stopper against which a spring receiving plate 28A on one side, which will be described later, comes into contact. A retaining ring 27G is provided at the other end of the spool 27 via an annular groove 27F. This retaining ring 27G constitutes a stopper against which a spring receiving plate 28B on the other side, which will be described later, comes into contact.

The spring receiving plates 28A and 28B are formed of annular plates and are provided on the other side of the spool 27. The spring receiving plate 28A is positioned in the axial direction by contacting the annular convex portion 27E of the spool 27 from the other side, and the spring receiving plate 28B is positioned in the axial direction by contacting the retaining ring 27G of the spool 27 from one side. ing.

The spring member 29 is located on the outer peripheral side of the spool 27 and is provided between each spring receiving plate 28A, 28B. The spring member 29 is formed as a compression coil spring. The spring member 29 urges the spool 27 toward the neutral position shown in FIG. 4 by pressing the spring receiving plate 28A against the annular convex portion 27E and pressing the spring receiving plate 28B against the spring receiver 30.

The spring receiver 30 is formed as a cylindrical body inserted into the spring receiver accommodating portion 23C of the case body 23. The inside of the spring receiver 30 is a piston sliding portion 30A into which the other side common piston 33 is inserted so as to be movable in the axial direction.

A feedback link 31 is provided between the servo piston 19 and the control sleeve 26. The feedback link 31 is a link member that performs feedback control of the control sleeve 26 of the regulator 21 by following the movement of the servo piston 19. As shown in FIGS. 1 and 3, the base end side of the feedback link 31 in the length direction is swingably engaged (connected) to the link engagement groove 26E of the control sleeve 26 via the pin member 31A. . The tip portion 31B of the feedback link 31 is engaged with the link attachment groove 19C of the servo piston 19. A fulcrum pin 31C is provided at a longitudinally intermediate portion of the feedback link 31 so as to extend in the radial direction of the casing 2. This fulcrum pin 31C is rotatably attached to the casing body 3 at the position of the opening 3C. Thereby, the feedback link 31 is swung in one direction and the other direction (arrow A direction and arrow B direction) about the fulcrum pin 31C.

The one-side common piston 32 is located between the one-side block 24 and the spool 27 and is provided in the sleeve sliding portion 23A of the case body 23. The one side common piston 32 has a large diameter portion 32A that is slidably provided within the sleeve sliding portion 23A, and a small diameter portion 32B that protrudes from the center of the other side of the large diameter portion 32A and can enter the control sleeve 26. It is composed of. The tip of the small diameter portion 32B is in contact with one side end surface 27A of the spool 27. On the other hand, a first main piston 34 and a first sub-piston 38, which will be described later, are in contact with one end surface of the large diameter portion 32A.

The one-side common piston 32 is pressed when the large diameter portion 32A is pushed by the first main piston 34, when the large diameter portion 32A is pushed by the first sub-piston 38, or by both pistons 34, 38. In either case, the spool 27 can be pushed toward the other side by the small diameter portion 32B.

The other side common piston 33 is located between the other side block 25 and the spool 27 and is provided in the piston sliding portion 30A of the spring receiver 30. Like the one side common piston 32, the other side common piston 33 includes a large diameter portion 33A and a small diameter portion 33B. The tip of the small diameter portion 33B is in contact with the other end surface 27B of the spool 27. On the other hand, a second main piston 36 and a second sub-piston 40, which will be described later, are in contact with the other end surface of the large diameter portion 33A.

The other side common piston 33 is pushed when the large diameter portion 33A is pushed by the second main piston 36, when the large diameter portion 33A is pushed by the second sub-piston 40, or by both pistons 36 and 40. In either case, the spool 27 can be pushed toward one side by the small diameter portion 33B.

The first main piston 34 is fitted into the main small diameter cylinder 24A of the one side block 24 so as to be slidable in the axial direction. The first main piston 34 is made of a cylindrical body, and the end portion protruding from the main small diameter cylinder 24A is in contact with the large diameter portion 32A of the common piston 32 on one side.

One pilot pressure chamber 35 is formed between the main small diameter cylinder 24A of the one side block 24 that constitutes the regulator casing 22 and the first main piston 34. That is, one pilot pressure chamber 35 is a space formed between the first main piston 34 and the regulator casing 22 (one side block 24). Operating pressure for operating the spool 27 in the other direction (arrow B direction) is supplied to one pilot pressure chamber 35 through the pilot port 24C. Thereby, one pilot pressure chamber 35 can operate the spool 27 in the direction of arrow B via the first main piston 34 and the one side common piston 32.

The second main piston 36 is fitted into the main small diameter cylinder 25A of the other side block 25 so as to be slidable in the axial direction. The second main piston 36 is made of a cylindrical body, and the end portion protruding from the main small diameter cylinder 25A is in contact with the large diameter portion 33A of the other side common piston 33.

Another pilot pressure chamber 37 is formed between the main small-diameter cylinder 25A of the other side block 25 that constitutes the regulator casing 22 and the second main piston 36. That is, the other pilot pressure chamber 37 is a space formed between the second main piston 36 and the regulator casing 22 (the other side block 25). Operating pressure for operating the spool 27 in one direction (arrow A direction) is supplied to the other pilot pressure chamber 37 through the pilot port 25C. Thereby, the other pilot pressure chamber 37 can operate the spool 27 in the direction of arrow A via the second main piston 36 and the other side common piston 33.

The first sub-piston 38 is fitted into the sub-small diameter cylinder 24B of the one-side block 24 so as to be slidable in the axial direction. Thereby, the first main piston 34 and the first sub-piston 38 are arranged side by side in the radial direction perpendicular to the axis of the spool 27. The first sub-piston 38 is made of a cylindrical body, and the end portion protruding from the sub-small diameter cylinder 24B is in contact with the large-diameter portion 32A of the one side common piston 32.

One auxiliary pressure chamber 39 is located on one side of the spool 27 and moves the spool 27 in the other direction. The one auxiliary pressure chamber 39 is independent from the one pilot pressure chamber 35 and is formed between the sub small diameter cylinder 24B of the one side block 24 that constitutes the regulator casing 22 and the first sub piston 38. That is, one auxiliary pressure chamber 39 is a space formed between the first sub-piston 38 and the regulator casing 22 (one side block 24). The pressure of the hydraulic fluid flowing out from the other hydraulic pressure chamber 20B is applied to one of the auxiliary pressure chambers 39 as the operating pressure for operating the spool 27 in the other direction (arrow B direction). It is supplied through the first auxiliary passage 44 and the auxiliary port 24D. As a result, one auxiliary pressure chamber 39 applies a pressing force to move the spool 27 in the direction of arrow B via the first sub-piston 38 and the one-side common piston 32.

The second sub-piston 40 is fitted into the sub-small diameter cylinder 25B of the other side block 25 so as to be slidable in the axial direction. Thereby, the second main piston 36 and the second sub-piston 40 are arranged side by side in the radial direction perpendicular to the axis of the spool 27. The second sub-piston 40 is made of a cylindrical body, and the end portion protruding from the sub-small diameter cylinder 25B is in contact with the large-diameter portion 32A of the other side common piston 33.

Another auxiliary pressure chamber 41 is provided on the other side of the spool 27 and moves the spool 27 in one direction. The other auxiliary pressure chamber 41 is independent from the other pilot pressure chamber 37 and is formed between the sub small diameter cylinder 25B of the other side block 25 and the second sub piston 40 that constitute the regulator casing 22. That is, the other auxiliary pressure chamber 41 is a space formed between the second sub-piston 40 and the regulator casing 22 (the other side block 25). In the other auxiliary pressure chamber 41, the pressure of the hydraulic oil flowing out from the one hydraulic pressure chamber 20A is used as the operating pressure for moving the spool 27 in one direction (arrow A direction). It is supplied through the second auxiliary passage 45 and the auxiliary port 25D. As a result, the other auxiliary pressure chamber 41 applies a pressing force to move the spool 27 in the direction of arrow A via the second sub-piston 40 and the other side common piston 33.

One hydraulic pressure passage 42 connects one hydraulic pressure chamber 20A and regulator 21. Specifically, one hydraulic pressure passage 42 connects one hydraulic pressure chamber 20A and one side actuator port 23F forming the case body 23 of the regulator casing 22.

The other hydraulic pressure passage 43 connects the other hydraulic pressure chamber 20B and the regulator 21. Specifically, the other hydraulic pressure passage 43 connects the other hydraulic pressure chamber 20B and the other side actuator port 23G forming the case body 23 of the regulator casing 22.

The first auxiliary passage 44 is provided to connect one auxiliary pressure chamber 39 and another hydraulic pressure passage 43. The first auxiliary passage 44 is a passage for causing the pressure of the other hydraulic pressure passage 43 to act on the first sub-piston 38 in the one auxiliary pressure chamber 39 via the auxiliary port 24D of the one side block 24.

The second auxiliary passage 45 is provided to connect another auxiliary pressure chamber 41 and one hydraulic pressure passage 42 . The second auxiliary passage 45 is a passage for causing the pressure of one hydraulic pressure passage 42 to act on the second sub-piston 40 in the other auxiliary pressure chamber 41 via the auxiliary port 25D of the other side block 25.

The variable displacement swash plate hydraulic pump 1 according to this embodiment has the above-described configuration. Next, when the variable capacity part (swash plate 11, etc.) of the swash plate type hydraulic pump 1 is tilted and driven in both one direction and the other direction from the neutral position where the tilt angle is 0 degrees (the neutral position shown in FIG. 3). The capacity control operation by the regulator 21 will be explained.

In this embodiment, in order to clarify that the operation and effect of this embodiment are superior to those of the prior art, the regulator 21 is used without using the configuration that is the feature of this embodiment. A case where the servo piston 19 of the rotary actuator 16 is operated, that is, an operation similar to that of the prior art will be described.

As shown in FIG. 4, a case will be described in which the swash plate 11 of the hydraulic pump 1 is tilted and driven in the direction of arrow A, which is one direction, from a neutral position where the tilt angle is 0 degrees. In this case, as shown by arrow a, pilot pressure is supplied from the first tilt operation valve to the first pilot pressure chamber 35 provided in the regulator 21 via the pilot pipe line and the pilot port 24C of the one side block 24. supply.

When pilot pressure is supplied to the one pilot pressure chamber 35, the first main piston 34 moves the spool 27 in the direction of arrow B along the spool sliding hole 26A of the control sleeve 26 via the one side common piston 32. Displace (move). At this time, the spool 27 is displaced in the direction of arrow B to a position where the pushing force of the first main piston 34 and the urging force of the spring member 29 are in equilibrium. When the spool 27 is displaced in the direction of arrow B, the oil hole 26B and oil hole 26D of the control sleeve 26 communicate with each other between the two lands 27C and 27D of the spool 27 via the spool sliding hole 26A. Thereby, the pump port 23E of the case body 23 is communicated with the other side actuator port 23G.

Pressure oil (tilting control pressure) supplied from the pilot pump to the pump port 23E is transmitted to the pump port 23E, the oil holes 26B and 26D of the control sleeve 26, and the other side actuator port 23G, as shown by arrow b. After flowing to the other hydraulic pressure chambers 20B, as shown by the arrow c, the liquid is supplied to the other hydraulic pressure chambers 20B through another hydraulic pressure passage 43. As a result, as shown in FIG. 5, the servo piston 19 is pushed by the pressure oil supplied to the other hydraulic pressure chamber 20B, and is displaced in the direction of arrow A within each cylinder hole 17A, 17B.

When the servo piston 19 is displaced in the direction of arrow A, the feedback link 31 displaces the control sleeve 26 of the regulator 21 in the direction of arrow B, which is the same direction of displacement of the spool 27. Thereby, the control sleeve 26 is feedback-controlled to a position where the oil holes 26C, 26D are blocked (closed) from the inner spool sliding hole 26A by the lands 27C, 27D of the spool 27.

The tilting actuator 16 then tilts the swash plate 11 in the direction of arrow A via the tilting lever 12. In this case, the tilt actuator 16 tilts the tilt angle of the swash plate 11 to the set tilt angle (target tilt angle).

In this way, when the spool 27 is moved using only the pilot pressure supplied to one pilot pressure chamber 35, the control sleeve 26 catches up with the spool 27 being moved in the direction of arrow B, and the oil hole of the control sleeve 26 Lands 27C and 27D of spool 27 squeeze 26C and 26D. As a result, as shown by the dotted line in FIG. 8, due to the existence of the movement speed reduction section, it takes time for the swash plate of the tilting actuator 16 to reach the target tilting angle.

Next, a case will be described in which the servo piston 19 of the tilting actuator 16 is operated by the regulator 21 using the configuration that is a feature of this embodiment.

As shown in FIG. 4, when tilting and driving the swash plate 11 of the hydraulic pump 1 in the direction of arrow A, which is one direction, from the neutral position where the tilt angle is 0 degrees, as shown by arrow a. Then, pilot pressure is supplied from the first tilt operation valve to the first pilot pressure chamber 35 provided in the regulator 21 via the pilot pipe and the pilot port 24C of the one side block 24.

When pilot pressure is supplied to the one pilot pressure chamber 35, the first main piston 34 moves the spool 27 in the direction of arrow B along the spool sliding hole 26A of the control sleeve 26 via the one side common piston 32. Displace (move). At this time, the spool 27 is displaced in the direction of arrow B to a position where the pushing force of the first main piston 34 and the urging force of the spring member 29 are in equilibrium. When the spool 27 is displaced in the direction of arrow B, the oil hole 26B and oil hole 26D of the control sleeve 26 communicate with each other between the two lands 27C and 27D of the spool 27 via the spool sliding hole 26A. Thereby, the pump port 23E of the case body 23 is communicated with the other side actuator port 23G.

Pressure oil (tilting control pressure) supplied from the pilot pump to the pump port 23E is transmitted to the pump port 23E, the oil holes 26B and 26D of the control sleeve 26, and the other side actuator port 23G, as shown by arrow b. After flowing to the other hydraulic pressure chambers 20B, as shown by the arrow c, the liquid is supplied to the other hydraulic pressure chambers 20B through another hydraulic pressure passage 43. As a result, as shown in FIG. 5, the servo piston 19 is pushed by the pressure oil supplied to the other hydraulic pressure chamber 20B, and is displaced in the direction of arrow A within each cylinder hole 17A, 17B.

Here, since the first auxiliary passage 44 is connected to the other hydraulic pressure passage 43, a part of the pressure oil supplied to the other hydraulic pressure chamber 20B is, as shown by the arrow d, It is supplied to one auxiliary pressure chamber 39 through the first auxiliary passage 44 and the auxiliary port 24D of the one side block 24. The regulator 21 displaces the first sub-piston 38 in the direction of arrow B using the pressure oil (operating pressure of the servo piston 19) supplied to the one auxiliary pressure chamber 39. Thereby, the first sub-piston 38 can push the spool 27 in the direction of arrow B via the one-side common piston 32.

On the other hand, the first hydraulic pressure chamber 20A is connected to the first hydraulic pressure passage 42, the one side actuator port 23F of the case body 23, the oil hole 26C of the control sleeve 26, the drain passage 23H, the spring housing part 23B, the link insertion hole 23J, etc. It is connected to the casing body 3 on the drain side. Therefore, the other auxiliary pressure chamber 41 connected to the first hydraulic pressure passage 42 via the second auxiliary passage 45 and the auxiliary port 25D of the other side block 25 has a tank pressure close to atmospheric pressure. The second sub-piston 40 does not interfere with the movement of the spool 27 that is pushed in the direction of arrow B. Thereby, as shown in FIG. 6, the spool 27 can be largely displaced in the direction of arrow B.

Furthermore, when the control sleeve 26 catches up with the spool 27 being moved in the direction of arrow B, the one side actuator port 23F is throttled and the pressure in one hydraulic pressure passage 42 is increased, so that the pressure in the other auxiliary pressure chamber 41 is also increased. Boosted. As a result, as shown in FIG. 7, the second sub-piston 40 pushes the spool 27 in the direction of arrow A via the other-side common piston 33. Then, the spool 27 stops at a position where the resultant force of the first main piston 34 and the first sub-piston 38, the urging force of the spring member 29, and the force of the second sub-piston 40 are in equilibrium. Further, the control sleeve 26 stops at a position where the pressure in one hydraulic pressure chamber 20A, the pressure in the other hydraulic pressure chamber 20B, and the external force acting on the servo piston 19 are in equilibrium.

In this way, since the spool 27 is pushed by the sum of the pushing force of the first main piston 34 and the pushing force of the first sub-piston 38, the spool 27 can be largely displaced, and the case body The opening time of the other side actuator port 23G of 23 can be extended compared to the prior art. As a result, a large amount of pressure oil can be supplied to the other hydraulic pressure chambers 20B until the control sleeve 26 catches up with the spool 27 moved in the direction of arrow B.

Next, a case will be described in which the swash plate 11 of the hydraulic pump 1 is tilted and driven in the direction of arrow B, which is another direction, from the neutral position where the tilt angle is 0 degrees. In this case, pilot pressure is supplied from another tilt operation valve to another pilot pressure chamber 37 provided in the regulator 21 via the pilot pipe and the pilot port 25C of the other side block 25.

When pilot pressure is supplied to the other pilot pressure chamber 37, the second main piston 36 moves the spool 27 in the direction of arrow A along the spool sliding hole 26A of the control sleeve 26 via the other side common piston 33. Displace (move). At this time, the spool 27 is displaced in the direction of arrow A to a position where the pushing force of the second main piston 36 and the urging force of the spring member 29 are balanced. When the spool 27 is displaced in the direction of arrow A, the oil hole 26B and oil hole 26C of the control sleeve 26 communicate between the two lands 27C and 27D of the spool 27 via the spool sliding hole 26A. Thereby, the pump port 23E of the case body 23 is communicated with the one-side actuator port 23F.

Then, the pressure oil (tilting control pressure) supplied from the pilot pump to the pump port 23E flows through the pump port 23E, the oil holes 26B and 26C of the control sleeve 26, and the one side actuator port 23F, and then flows into the one side actuator port 23F. It is supplied to one hydraulic pressure chamber 20A through the pressure passage 42. Thereby, the servo piston 19 is pushed by the pressure oil supplied to one hydraulic pressure chamber 20A, and is displaced in the direction of arrow B within each cylinder hole 17A, 17B.

Here, since the second auxiliary passage 45 is connected to the one hydraulic pressure passage 42, a part of the pressure oil supplied to the one hydraulic pressure chamber 20A is transferred to the second auxiliary passage 45, the other side. It is supplied to other auxiliary pressure chambers 41 through the auxiliary port 25D of the block 25. The regulator 21 displaces the second sub-piston 40 in the direction of arrow A using the pressure oil (operating pressure of the servo piston 19) supplied to the other auxiliary pressure chamber 41. Thereby, the second sub-piston 40 can push the spool 27 in the direction of arrow A via the other-side common piston 33.

On the other hand, the other hydraulic pressure chamber 20B is connected to the hydraulic oil tank (see Fig. (not shown). Therefore, the first auxiliary pressure chamber 39 connected to the other hydraulic pressure passage 44 via the first auxiliary passage 44 and the auxiliary port 24D of the one side block 24 has a tank pressure close to atmospheric pressure. The first sub-piston 38 does not interfere with the movement of the spool 27 that is pushed in the direction of arrow A. Thereby, the spool 27 can be largely displaced in the direction of arrow A.

Furthermore, when the control sleeve 26 catches up with the spool 27 being moved in the direction of arrow A, the other side actuator port 23G is throttled and the pressure of the other hydraulic pressure passage 43 is increased, so that the one auxiliary pressure chamber 39 is also Boosted. As a result, the first sub-piston 38 pushes the spool 27 in the direction of arrow B via the one-side common piston 32. Then, the spool 27 stops at a position where the resultant force of the second main piston 36 and the second sub-piston 40, the urging force of the spring member 29, and the force of the first sub-piston 38 are in equilibrium. Further, the control sleeve 26 stops at a position where the pressure in one hydraulic pressure chamber 20A, the pressure in the other hydraulic pressure chamber 20B, and the external force acting on the servo piston 19 are in equilibrium.

In this way, since the spool 27 is pushed by the sum of the pushing force of the second main piston 36 and the pushing force of the second sub-piston 40, the spool 27 can be largely displaced, and the case body The open time of one side actuator port 23F of 23 can be extended compared to the conventional technology. As a result, a large amount of pressure oil can be supplied to one hydraulic pressure chamber 20A until the control sleeve 26 catches up with the spool 27 moved in the direction of arrow A.

Thus, according to the first embodiment, the regulator casing 22 is provided with a pilot pressure located on one side of the spool 27 in order to move the spool 27 in the direction of arrow B, which is the other direction. One auxiliary pressure chamber 39 is independent of the chamber 35 and is provided on the other side of the spool 27 in order to move the spool 27 in one direction, which is the direction of arrow B, and is independent of the other pilot pressure chamber 37. and another auxiliary pressure chamber 41. Furthermore, a first auxiliary passage 44 that connects one auxiliary pressure chamber 39 and another hydraulic pressure passage 43 and a second auxiliary passage 45 that connects another auxiliary pressure chamber 41 and one hydraulic pressure passage 42 are connected to each other. It is provided.

Therefore, the spool 27 can be pushed in the direction of the arrow B by the total pushing force of the first main piston 34 and the first sub-piston 38, and the pushing force of the second main piston 36 It can be pushed in the direction of arrow A with the total pressing force of this and the pressing force of the second sub-piston 40. Thereby, the spool 27 can be largely displaced. As a result, the servo piston 19 of the tilting actuator 16 can be moved to the target position in a short time.

A first main piston 34 and a first sub-piston 38 are provided on one end of the spool 27 in a radial direction perpendicular to the axis of the spool 27. Further, on the other end side of the spool 27, a second main piston 36 and a second sub-piston 40 are provided side by side in a radial direction perpendicular to the axis of the spool 27. The space formed between the first main piston 34 and the regulator casing 22 is one pilot pressure chamber 35, and the space formed between the second main piston 36 and the regulator casing 22 is another pilot pressure chamber. This is a pressure chamber 37. Further, the space formed between the first sub-piston 38 and the regulator casing 22 is one auxiliary pressure chamber 39, and the space formed between the second sub-piston 40 and the regulator casing 22 is another auxiliary pressure chamber. This is a pressure chamber 41.

Thereby, the first main piston 34 and the first sub-piston 38, and the second main piston 36 and the second sub-piston 40, which are arranged side by side in the radial direction, can be formed compactly in the length direction of the regulator 21. , the hydraulic pump 1 can be downsized. Moreover, by making the pilot pressure chambers 35, 37 and the auxiliary pressure chambers 39, 41 completely independent, pressure leakage between the pilot pressure chambers 35, 37 and the auxiliary pressure chambers 39, 41 can be prevented, and the operating performance can be improved. can be improved.

Next, FIGS. 9 and 10 show a second embodiment of the present invention. In this embodiment, a first main piston and a first sub-piston that are arranged side by side in the axial direction of the spool and have different diameter dimensions are provided at one end of the spool, and a first main piston and a first sub-piston are provided at the other end of the spool in the axial direction of the spool. A second main piston and a second sub-piston are arranged side by side and have different diameter dimensions, the space formed between the first main piston and the regulator casing is one pilot pressure chamber, and the second main piston The space formed between the first sub-piston and the regulator casing is another pilot pressure chamber, the space formed between the first sub-piston and the regulator casing is one auxiliary pressure chamber, and the space formed between the second sub-piston and the regulator casing is an auxiliary pressure chamber. It is characterized in that the space formed between it and the casing is another auxiliary pressure chamber. In addition, in the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

In FIG. 9, a regulator 51 according to the second embodiment includes the control sleeve 26, the feedback link 31, a regulator casing 52, a spool 55, one pilot pressure chamber 58, another pilot pressure chamber 59, and one pilot pressure chamber 59, which will be described later. It is configured to include an auxiliary pressure chamber 60 and another auxiliary pressure chamber 61.

The regulator casing 52 has one side block 53 provided on one side of the case body 23 in the axial direction (the left side in FIG. 9), and a block 53 provided on the other side of the case body 23 in the axial direction (the right side in FIG. 9). and a side block 54.

The one side block 53 is provided with a main cylinder 53A that is open at the end face on the case body 23 side, and a sub cylinder 53B that extends from the bottom of the main cylinder 53A. The main cylinder 53A and the sub-cylinder 53B are arranged, for example, on the same axis as a spool 55, which will be described later, that is, aligned in the axial direction of the spool 55. Further, the main cylinder 53A is formed to have a larger diameter than the sub cylinder 53B.

Further, the one side block 53 is provided with a pilot port 53C communicating with the main cylinder 53A and an auxiliary port 53D communicating with the sub cylinder 53B. The pilot port 53C is connected to one tilt operation valve (none of which is shown) via a pilot pipe. The auxiliary port 53D is connected to another hydraulic pressure passage 43 via the first auxiliary passage 44.

On the other hand, the other side block 54, like the one side block 53, includes a main cylinder 54A, a sub cylinder 54B, a pilot port 54C, and an auxiliary port 54D. The pilot port 54C is connected to other tilt operation valves (none of which are shown) via a pilot pipe. The auxiliary port 54D is connected to the one hydraulic pressure passage 42 via the second auxiliary passage 45.

The spool 55 is provided within the regulator casing 52, that is, in the sleeve sliding portion 23A of the case body 23 via the control sleeve 26 so as to be relatively movable. Like the spool 27 according to the first embodiment, the spool 55 includes an end surface 55A on one side, an end surface 55B on the other side, lands 55C and 55D, an annular protrusion 55E, an annular groove 55F, and a retaining ring 55G.

The one-side stepped piston 56 is inserted and fitted across the main cylinder 53A and sub-cylinder 53B of the one-side block 53 so as to be slidable in the axial direction. The one side stepped piston 56 is provided with a large diameter first main piston 56A inserted into the main cylinder 53A and an end of the first main piston 56A extending coaxially, and has a smaller diameter than the first main piston 56A. and a first sub-piston 56B. The first main piston 56A has an annular pressure receiving surface 56C at a step between it and the first sub-piston 56B. Further, the first sub-piston 56B has a circular pressure-receiving surface 56D on the end surface opposite to the first main piston 56A.

Here, as shown in FIG. 10, the diameter of the first main piston 56A is D1, and the diameter of the first sub-piston 56B is D2, which is smaller than the diameter D1. The relationship between the diameter dimension D1 and the diameter dimension D2 is such that the pressing force when the annular pressure receiving surface 56C of the first main piston 56A receives the pilot pressure is the same as that when the circular pressure receiving surface 56D of the first sub-piston 56B receives the servo piston 19. The respective diameter dimensions are set in consideration of area and pressure so that the pressure is greater than the pressing force when receiving the operating pressure of .

The other side stepped piston 57 is inserted and fitted across the main cylinder 54A and the sub cylinder 54B of the other side block 54 so as to be slidable in the axial direction. The other side stepped piston 57 has the same shape as the one side stepped piston 56. That is, the other side stepped piston 57 includes a second main piston 57A, a second sub-piston 57B, an annular pressure receiving surface 57C, and a circular pressure receiving surface 57D.

One pilot pressure chamber 58 is formed between the main cylinder 53A of the one side block 53 and the first main piston 56A of the one side stepped piston 56 that constitute the regulator casing 52. That is, one pilot pressure chamber 58 is an annular space formed between the first main piston 56A and the regulator casing 52 (one side block 53). Operating pressure for operating the spool 55 in the other direction is supplied to one pilot pressure chamber 58 through the pilot port 53C. Thereby, one pilot pressure chamber 58 can operate the spool 55 in the other direction via the first main piston 56A of the stepped piston 56 on one side.

Another pilot pressure chamber 59 is formed between the main cylinder 54A of the other side block 54 and the second main piston 57A of the other side stepped piston 57 that constitute the regulator casing 52. That is, the other pilot pressure chamber 59 is an annular space formed between the second main piston 57A and the regulator casing 52 (the other side block 54). Operating pressure for operating the spool 55 in one direction is supplied to the other pilot pressure chamber 59 through the pilot port 54C. Thereby, the other pilot pressure chamber 59 can operate the spool 55 in one direction via the second main piston 57A of the stepped piston 57 on the other side.

One auxiliary pressure chamber 60 is located on one side of the spool 55 and moves the spool 55 in the other direction. The one auxiliary pressure chamber 60 is independent of the one pilot pressure chamber 58 and is located between the sub-cylinder 53B of the one-side block 53 that constitutes the regulator casing 52 and the first sub-piston 56B of the one-side stepped piston 56. is formed. That is, one auxiliary pressure chamber 60 is a circular space formed between the first sub-piston 56B and the regulator casing 52 (one side block 53). The pressure of the hydraulic oil flowing out from the other hydraulic pressure chamber 20B is applied to one auxiliary pressure chamber 60 as an operating pressure for moving the spool 55 in the other direction. It is supplied through the auxiliary port 53D. As a result, one auxiliary pressure chamber 60 applies a pressing force to move the spool 55 in the other direction via the stepped piston 56 on one side.

Another auxiliary pressure chamber 61 is provided on the other side of the spool 55 and moves the spool 55 in one direction. The other auxiliary pressure chamber 61 is independent of the other pilot pressure chamber 59 and is located between the sub-cylinder 54B of the other side block 54 and the second sub-piston 57B of the other side stepped piston 57 that constitute the regulator casing 52. is formed. That is, the other auxiliary pressure chamber 61 is a circular space formed between the second sub-piston 57B and the regulator casing 52 (the other side block 54). In the other auxiliary pressure chamber 61, the pressure of the hydraulic oil flowing out from the one hydraulic pressure chamber 20A as the operating pressure for moving the spool 55 in one direction is one hydraulic pressure passage 42, a second auxiliary passage 45, It is supplied through the auxiliary port 54D. As a result, the other auxiliary pressure chamber 61 applies a pressing force to move the spool 55 in one direction via the stepped piston 57 on the other side.

The drain passage 62 is provided so as to communicate the sub-cylinder 53B of the one-side block 53 into the sleeve sliding portion 23A of the case body 23. The drain passage 62 prevents the pressure oil supplied to the one auxiliary pressure chamber 60 from flowing into the one pilot pressure chamber 58. Similarly, the drain passage 63 is provided so as to communicate the sub-cylinder 54B of the other side block 54 into the spring receiver accommodating portion 23C (inside the spring receiver 30) of the case body 23.

Note that the operation when tilting the swash plate 11 of the hydraulic pump 1 by the regulator 51 according to the second embodiment is the same as that of the regulator 21 according to the first embodiment, so a description thereof will be omitted.

Thus, in the second embodiment configured in this manner, substantially the same functions and effects as those of the first embodiment described above can be obtained. In particular, according to the second embodiment, one end of the spool 55 is provided with a first main piston 56A and a first sub-piston 56B that are arranged side by side in the axial direction of the spool 55 and have different diameter dimensions. The other side stepped piston 56 has a stepped piston 56, and the other end side of the spool 55 is provided with a second main piston 57A and a second sub-piston 57B that are arranged side by side in the axial direction of the spool 55 and have different diameter dimensions. It has a piston 57. Further, the space formed between the first main piston 56A and the block 53 on one side of the regulator casing 52 is one pilot pressure chamber 58, and the space formed between the second main piston 57A and the block 54 on the other side of the regulator casing 52 is a pilot pressure chamber 58. The space formed in between is another pilot pressure chamber 59. Furthermore, the space formed between the first sub-piston 56B and the block 53 on one side of the regulator casing 52 is one auxiliary pressure chamber 60, and the space formed between the second sub-piston 57B and the block 54 on the other side of the regulator casing 52 is The space formed in between is another auxiliary pressure chamber 61.

With this configuration, the common pistons 32 and 33 of the first embodiment can be omitted, and each cylinder 53A, 53B, 54A, 54B and each stepped piston 56, 57 can be easily machined. can.

In each of the embodiments, a case where the present invention is applied to a variable displacement swash plate hydraulic pump 1 as a variable displacement hydraulic rotary machine has been described as an example. However, the present invention is not limited thereto, and may be applied, for example, to a variable displacement swash plate type hydraulic motor, or to a variable displacement type slant axis hydraulic pump or hydraulic motor.

1 Variable displacement swash plate hydraulic pump (variable displacement hydraulic rotating machine)
11 Swash plate (variable capacity part)
16 Tilt actuator 17A, 17B Cylinder hole 19 Servo piston 19A One end 19B Other end 20A One hydraulic chamber 20B Other hydraulic chamber 21, 51 Regulator 22, 52 Regulator casing 23 Case body 23A Sleeve sliding part (cylindrical hole)
26 Control sleeve 27,55 Spool 31 Feedback link 34,56A First main piston 35,58 One pilot pressure chamber 36,57A Second main piston 37,59 Other pilot pressure chamber 38,56B First sub-piston 39,60 One auxiliary pressure chamber 40, 57B Second sub-piston 41, 61 Other auxiliary pressure chamber 42 One hydraulic pressure passage 43 Other hydraulic passage 44 First auxiliary passage 45 Second auxiliary passage

Claims (3)

a tilting actuator in which a servo piston is movably inserted into a cylinder hole in order to tilt the variable capacity part;
a regulator that drives the servo piston of the tilting actuator;
one hydraulic pressure passage connecting one hydraulic pressure chamber formed between one end of the servo piston and the cylinder hole and the regulator;
another hydraulic pressure passage connecting the regulator to another hydraulic pressure chamber formed between the other end of the servo piston and the cylinder hole,
The regulator is
a regulator casing provided with a cylindrical hole;
a spool that is provided in the regulator casing so as to be relatively displaceable via a control sleeve, and supplies and discharges tilting control pressure for operating the servo piston to and from each of the hydraulic pressure chambers through the hydraulic pressure passage;
a feedback link disposed between the servo piston and the control sleeve for transmitting displacement of the servo piston to the control sleeve;
a pilot pressure chamber located on one side of the spool and provided in the regulator casing to move the spool in the other direction;
A variable displacement hydraulic rotating machine configured to include another pilot pressure chamber located on the other side of the spool and provided in the regulator casing for operating the spool in one direction,
The regulator casing includes one auxiliary pressure chamber, which is located on one side of the spool and is independent of the one pilot pressure chamber, for moving the spool in the other direction. further comprising another auxiliary pressure chamber located on the other side of the spool and independent of the other pilot pressure chamber for operation in the direction;
A first auxiliary passage that connects the one auxiliary pressure chamber and the other hydraulic pressure passage, and a second auxiliary passage that connects the other auxiliary pressure chamber and the one hydraulic pressure passage are provided. A variable displacement hydraulic rotary machine characterized by: The variable displacement hydraulic rotating machine according to claim 1,
A first main piston and a first sub-piston are provided on one end side of the spool in a radial direction perpendicular to the axis of the spool,
A second main piston and a second sub-piston are provided on the other end of the spool in a radial direction perpendicular to the axis of the spool,
A space formed between the first main piston and the regulator casing is the first pilot pressure chamber,
A space formed between the second main piston and the regulator casing is the other pilot pressure chamber,
A space formed between the first sub-piston and the regulator casing is the one auxiliary pressure chamber,
A variable displacement hydraulic rotating machine, wherein a space formed between the second sub-piston and the regulator casing is the other auxiliary pressure chamber. The variable displacement hydraulic rotating machine according to claim 1,
A first main piston and a first sub-piston that are arranged in parallel in the axial direction of the spool and have different diameter dimensions are provided on one end side of the spool,
A second main piston and a second sub-piston are provided on the other end side of the spool and are arranged side by side in the axial direction of the spool and have different diameter dimensions,
A space formed between the first main piston and the regulator casing is the first pilot pressure chamber,
A space formed between the second main piston and the regulator casing is the other pilot pressure chamber,
A space formed between the first sub-piston and the regulator casing is the one auxiliary pressure chamber,
A variable displacement hydraulic rotating machine, wherein a space formed between the second sub-piston and the regulator casing is the other auxiliary pressure chamber.

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