EP0821163A1 - Gerät zum kontrollieren von taumelscheibenpumpe und motor - Google Patents

Gerät zum kontrollieren von taumelscheibenpumpe und motor Download PDF

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Publication number
EP0821163A1
EP0821163A1 EP96909350A EP96909350A EP0821163A1 EP 0821163 A1 EP0821163 A1 EP 0821163A1 EP 96909350 A EP96909350 A EP 96909350A EP 96909350 A EP96909350 A EP 96909350A EP 0821163 A1 EP0821163 A1 EP 0821163A1
Authority
EP
European Patent Office
Prior art keywords
swash
piston
port
spool
receiving chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96909350A
Other languages
English (en)
French (fr)
Other versions
EP0821163A4 (de
Inventor
Kenji Oyama Factory of Komatsu Ltd. MORINO
Yosuke Oyama Factory of Komatsu Ltd. ODA
Seita Oyama Factory of Komatsu Ltd. HAYASHI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Komatsu Ltd
Original Assignee
Komatsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Komatsu Ltd filed Critical Komatsu Ltd
Publication of EP0821163A1 publication Critical patent/EP0821163A1/de
Publication of EP0821163A4 publication Critical patent/EP0821163A4/de
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
    • F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
    • F04B27/14—Control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
    • F04B1/26—Control
    • F04B1/30—Control of machines or pumps with rotary cylinder blocks
    • F04B1/32—Control of machines or pumps with rotary cylinder blocks by varying the relative positions of a swash plate and a cylinder block
    • F04B1/324—Control of machines or pumps with rotary cylinder blocks by varying the relative positions of a swash plate and a cylinder block by changing the inclination of the swash plate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/08—Regulating by delivery pressure

Definitions

  • the present invention relates to a swash-plate controlling apparatus for a swash-plate type pump or a swash-plate type motor enabling to set an input torque and an output torque to an almost constant value by controlling a tilting angle of the swash-plate for the swash-plate type pump and the swash-plate type motor.
  • a swash-plate type pump is a pump in which a discharge amount (capacity) per unit number of rotation is controlled to be increased or decreased by tilting the swash-plate.
  • the capacity becomes large when a tilting angle of the swash plate is increased, while a small capacity is given for a decreased tilting angle.
  • An input torque of the swash-plate type pump is calculated by multiplying a pressure of a delivered pressurized-oil by the capacity.
  • a swash-plate type motor is one in which an influent amount (capacity) per unit number of rotation is controlled to be increased or decreased by tilting the swash-plate.
  • the capacity becomes large when a tilting angle of the swash-plate is increased, while a small capacity is given for a decreased tilting angle.
  • An output torque of the swash-plate type motor is calculated by multiplying a pressure of a supplied pressurized-oil by the capacity.
  • the apparatus described above is constructed in a manner that a first pushing device and a servo valve are provided in a housing, so that the first pushing device pushes the swash-plate in a direction for decreasing the tilting angle or the servo valve pushes the swash-plate in a direction for increasing the tilting angle.
  • the servo valve comprises: a housing; a piston slidably inserted into a first bore formed in the housing; a follow-up sleeve slidably inserted into a second bore formed in the housing; a servo spool valve slidably inserted into the follow-up sleeve; a load piston coaxially provided with regard to the servo spool valve; and a spring or the like for pushing the servo spool valve.
  • the tilting angle of the swash-plate is controlled by the first pushing device and the servo valve so as to take an angle which meets the delivery pressure of the swash-plate type pump.
  • the swash-plate controlling apparatus described above comprises the first pushing device and the servo valve, and further comprises a large number of parts or elements such as the housing, piston, follow-up sleeve, servo spool valve, load piston, spring or the like, so that assembling work of the apparatus will not only be complicated but also involve high cost due to large numbers of the parts or elements to be worked and assembled.
  • an overall size of the servo valve would become disadvantageously large, so that a large space is required for installing the housing, thereby to cause a problem that the swash-plate type pump would be assembled in a large size.
  • the present invention has been achieved for solving the above problems and an object of the present invention is to provide a swash-plate controlling apparatus for a swash-plate type pump or a swash-plate type motor which enables to simplify the assembling work of the apparatus due to the reduced number of the parts or elements, which can be manufactured at a low cost, and enables to manufacture the swash-plate type pump and the swash-plate type motor in a small size since an entire size of the apparatus is small and a space for installing the housing can be reduced.
  • the swash-plate controlling apparatus for the swash-plate type pump or the swash-plate type motor comprises: a housing; a cylinder bore formed in the housing; a piston slidably inserted into the cylinder bore; a large-sized pressure-receiving chamber and a small-sized pressure-receiving chamber defined at both end sides of the piston, respectively, for pushing the piston in one or another direction by the action of pressurized oil charged in the large-sized pressure-receiving chamber and the small-sized pressure-receiving chamber; a spool bore formed at an axial central portion of the piston; a spool slidably inserted into the spool bore; a first port, a second port and a drain port each provided between the piston and the spool for being communicated with or shut off from each other by the action of a relative movement of the piston and the spool; another pressure-receiving chamber defined at one end side of the spool
  • the swash-plate controlling apparatus adopts the basic construction in which the piston is inserted into the cylinder bore formed in the housing, the spool is inserted into the piston, and the spring for urging the spool is provided, so that it becomes possible to simplify the assembling work of the apparatus due to the reduced number of the parts or elements, and to manufacture the apparatus at a low cost.
  • an entire size of the apparatus becomes small and a space for installing the housing can be reduced, so that the swash-plate type pump and the swash-plate type motor can be manufactured in a small size.
  • the spring is preferably interposed among the bolt and the piston and the spool.
  • an urging force of the spring can be controlled. This means that a set value of the input torque of the swash-plate type pump or the output torque of the swash-plate type motor can be changed by a manual operation to be performed from outside the housing.
  • the spool is formed in a stepped-shape having a large-sized portion and a small-sized portion, the small-sized portion is formed so as to protrude to the small-sized pressure-receiving chamber, and a rod member of the plug fixed to the piston is fitted into an axial center portion of the large-sized portion formed in the spool, thereby to define a pressure-receiving chamber for changing the input torque so that an external pressure can be supplied to the pressure-receiving chamber for changing the input torque.
  • a swash-plate type pump 2 and a fixed-capacity type pump 3 are constructed so as to be driven by an engine 1.
  • a swash-plate 4 of the swash-plate type pump 2 is tilted by a piston 6 of a cylinder 5 through a link 16, and the piston 6 is pushed in a direction for decreasing the tilting angle by the action of the pressurized oil filling in the large-sized pressure-receiving chamber 7, or the piston 6 is pushed in a direction for increasing the tilting angle by the action of the spring 9 and the pressurized oil filling in the small-sized pressure-receiving chamber 8.
  • the large-sized pressure-receiving chamber 7 is connected to be switchable to either one of a tank 18 or a pump delivery path 11 (through the small-sized pressure-receiving chamber 8) by a switching operation of a change-over valve 10.
  • the small-sized pressure-receiving chamber 8 is normally connected to the pump delivery path 11 of the swash-plate type pump 2.
  • the change-over valve 10 is pushed to take a drain position A by the spring 12, or pushed to take a supply position B by the pressurized oil in a first pressure-receiving portion 13 and a second pressure-receiving portion 14.
  • the first pressure-receiving portion 13 is connected to the pump delivery path 11 of the swash-plate type pump 2 through the small-sized pressure-receiving chamber 8, and the second pressure-receiving portion 14 is connected to the delivery path 15 of the fixed-capacity type pump 3. Further, the spring 12 of the change-over valve 10 is connected to the piston 6 through the link 16, whereby a movement of the piston 6 is fed back to the change-over valve 10.
  • the piston 6 is pushed in a direction for decreasing the tilting angle by a pressure difference dependent on a difference in pressure-receiving areas between the large-sized pressure-receiving chamber 7 and the small-sized pressure-receiving chamber 8, so that the tilting angle of the swash-plate 4 is decreased thereby to reduce the capacity of the swash-plate type pump 2.
  • the swash-plate 4 is controlled so as to provide a tilting angle so that a product of the delivery pressure and the capacity (i.e., the input torque) would be an almost constant value.
  • the change-over valve 10 can be switched to take the supply position B by also the pressure in the second pressure-receiving portion 14, so that the input torque can be set to an arbitrary value by changing the pressure in the second pressure-receiving portion 14.
  • a shaft 22 is rotatably supported in the housing 20 and a cylinder block 21 is fixed to the shaft 22.
  • the cylinder block 21 is formed to have a plurality of cylinder bores 23 whose axes are parallel to an axis of the cylinder block 21.
  • a piston 24 is slidably inserted into the respective cylinder bores 23, and an end portion of the piston 24 is formed so as to slidably move along a front surface 4a of the swash-plate 4 through a shoe 19 in a circumferential direction of the swash-plate 4.
  • a piston chamber 25 of the cylinder bore 23 is alternately communicated with the main port 26 or the drain port (not shown).
  • a back surface 4b of the swash-plate 4 constitutes a part of a cylinder surface which is to be formed around a center axis contained in this specification paper, the center axis also being normal to the shaft 22 shown in FIG. 2.
  • the swash-plate 2 is swingably supported along a guide portion 27 which constitutes a part of the cylinder surface mating with the back surface 4b of the housing 20.
  • a slider 28 connected to the swash plate 4 is moved by a control apparatus 29 in a direction normal to this specification paper, the swash-plate 4 swings around the axis of the cylinder surface, thereby to change the tilting angle of the swash-plate 4.
  • the housing 20 has a large-sized first screw bore 30, a cylinder bore 31 and small-sized second screw bore 32 that are coaxially and continuously formed along the same center axis.
  • a first stopper 33 is screwed into the first screw bore 30 and is locked by a lock nut 34, while a second stopper 35 is screwed into the second screw bore 32 and is locked by another lock nut 36.
  • the cylinder bore 31 is formed in a stepped-shaped bore comprising a large-sized cylinder bore 37 and a small-sized cylinder bore 38.
  • a cutout portion 39 is formed at a part of a circumferential wall of the large-sized cylinder bore 37 so as to open toward a portion in the housing 20, and a slider 28 connected to the swash-plate 4 is positioned at the cutout portion 39.
  • a piston 40 is inserted into the cylinder bore 31, and the piston 40 is formed in a shape of stepped-piston comprising a large-sized piston 41 inserted into the large-sized cylinder bore 37 and a small-sized piston 42 inserted into the small-sized cylinder bore 38. Consequently, a large-sized pressure-receiving chamber 43 is formed between the large-sized piston 41 and the first stopper 33, while a small-sized pressure-receiving chamber 44 is formed between the large-sized piston 42 and the second stopper 35.
  • a spool bore 45 is formed at a center axial portion of the large-sized piston 41, while a large-sized bore 46 is formed at a center axial portion of the small-sized piston 42.
  • the spool bore 45 is formed in a shape of stepped-bore into which the spool 47 having a step is inserted.
  • a rod member 50 provided at a plug 49 inserted into a left end portion of the large-sized piston 41 is inserted, thereby to form a first pressure-receiving chamber 51, and the first pressure-receiving chamber 51 is communicated with an annular groove 52 of the large-sized portion 48.
  • the plug 49 is locked by a screw plug 53 screwed into the large-sized piston 41, and a second pressure-receiving chamber 54 is formed between the plug 49 and an end surface of the large-sized portion 48.
  • a bore 55 is formed in the axial direction, and one end portion of the bore 55 is opened toward an end surface of the small-sized portion 56 of the spool 47, thereby to be communicated with the small-sized pressure-receiving chamber 44.
  • the other end portion of the bore 55 is communicated with the first port 58 which is composed of an annular groove formed at an outer circumferential surface of the large-sized portion 48 through a bore 57 formed in a radial direction.
  • the first port 58 is communicated with the second pressure-receiving chamber 54 through a first small-sized hole 59 formed in a radial direction, a slit-shaped recessed portion 63 and a second small-sized hole 60, while the annular recessed portion 52 is communicated with an inlet port 64 through a third small-sized hole 61 formed in a radial direction and a slit-shaped recessed portion 62.
  • a second port 65 formed of an annular recessed portion and a drain port 66 formed of a small-sized bore are provided at the large-sized portion of the spool bore 45. Furthermore, the second port 65 is communicated with the large-sized pressure-receiving chamber 43 through a fourth small-sized hole 67 and a fifth small-sized hole 68.
  • the drain port 66 is communicated with an interior (tank) of the housing 20.
  • the small-sized pressure-receiving chamber 10 is communicated with the main port 26 through an oil bore 69 formed in the housing 20.
  • a bolt 70 is screw-engaged with the second stopper 35 and then fastened by a lock nut 71.
  • a spring 74 is provided between a receiver 72 provided at top end of the bolt 70 and a movable receiver 73.
  • the movable receiver 73 abuts against an end portion of the small-sized portion 56 formed on the spool 47 by the action of an urging force of the spring 74, thereby to push the spool 47 in a left direction in the figure.
  • the large-sized piston 41 is formed with a cutout recessed portion 75 to which the slider 28 is fitted and connected, whereby the piston 40 is connected to the swash-plate 4.
  • the spool 47 is pushed and displaced in the left direction by the action of the pressure P 1 applied to the end surface of the small-sized portion 56, or pushed in the right direction by the action of the pressure P 1 applied to the end surface of the large-sized portion 48.
  • a diameter of the small-sized portion 56 is d 1
  • a diameter of the rod member 50 is d 2
  • a diameter of the large-sized portion 48 is d 3
  • a driving force calculated from an equation of ⁇ /4 (d 3 2 - d 2 2 - d 1 2 ) ⁇ P 1 is applied to the spool 47 so as to move the spool 47 in the right direction.
  • the spool 47 When the driving force becomes larger than the urging force of the spring 47, the spool 47 is pushed in the right direction, so that the first port 58 is communicated with the second port 65, and a communication between the second port 65 and the drain port 66 is shut off, whereby the pressurized oil in the first port 58 flows into the large-sized pressure-receiving chamber 43 through the second port 65, the third small-sized hole 67 and the fourth small-sized hole 68. That is, the change-over valve 10 shown in FIG. 1 will be in a state taking the supplying position B, then the delivery pressure of the swash-plate pump 2 is applied to the large-sized pressure-receiving chamber 43.
  • the piston 40 When the pressurized oil flows into the large-sized pressure-receiving chamber 43, the piston 40 is pushed to move in the right direction by the action of the pressure difference caused by a difference between the pressure receiving areas of the large-sized pressure-receiving chamber 43 and the small-sized pressure-receiving chamber 44. As the result, the swash-plate 4 is tilted by the slider 28 in a direction for decreasing the tilting angle.
  • the piston 40 is stopped to a position corresponding to the delivery pressure.
  • the tilting angle of the swash-plate 4 i.e., the capacity of the swash-plate type pump 2 is controlled to be a value corresponding to the delivery pressure, whereby the input torque of the swash-plate type pump 2 can be set to a constant value as the set value.
  • the first pressure-receiving chamber 51 is equivalent to the second pressure-receiving chamber 14. Therefore, when the spool 47 is pushed to move rightward by the action of the pressurized oil in the first pressure-receiving chamber 51, the value of the input torque can be changed.
  • the set value of the input torque can also be changed.
  • the structure of the swash-plate controlling apparatus according to the present invention can also be applied to the swash-plate type motor in the same manner as in the swash-plate type pump.
  • the pressurized oil is supplied to the main port 26 from a hydraulic pump, so that the apparatus may be constructed so as to introduce the pressurized oil supplied from the hydraulic pump into the small-sized pressure-receiving chamber 44 through the main port 26 and the oil bore 69.
  • the tilting angle of the swash-plate is controlled to be an angle corresponding to the hydraulic pressure of the main port 26, so that the input torque of the swash-plate type pump or the output torque of the swash-plate type motor can be set to an almost constant value.
  • the swash-plate controlling apparatus adopts a basic structure in which the piston 40 is inserted into the cylinder bore 31 formed in the housing 20, the spool 47 is inserted into the piston 40, and the spring 74 for urging the spool 47 is provided, so that it becomes possible to simplify the assembling work of the apparatus due to the reduced number of the parts or elements, and to manufacture the apparatus at a low cost.
  • an entire size of the apparatus becomes small and a space for installing the housing can be reduced, so that the swash-plate type pump and the swash-plate type motor can be manufactured in a small size.
  • the urging force of the spring 74 can be controlled. This means that a set value of the input torque of the swash-plate type pump or the output torque of the swash-plate type motor can be changed by a manual operation to be performed from outside the housing.
  • the swash-plate controlling apparatus of the present invention when the pressure of the pressurized oil to be supplied to the pressure-receiving chamber 51 is changed, a force for pushing the spool 47 in one direction can be controlled, whereby the set value of the input torque of the swash-plate type pump or the output torque of the swash-plate type motor can be changed by an external hydraulic pressure.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Hydraulic Motors (AREA)
EP96909350A 1995-04-12 1996-04-11 Gerät zum kontrollieren von taumelscheibenpumpe und motor Withdrawn EP0821163A4 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP86687/95 1995-04-12
JP08668795A JP3672046B2 (ja) 1995-04-12 1995-04-12 斜板ポンプ・モータの斜板制御装置
PCT/JP1996/001006 WO1996032587A1 (fr) 1995-04-12 1996-04-11 Dispositif de commande d'une pompe et d'un moteur a disque en nutation

Publications (2)

Publication Number Publication Date
EP0821163A1 true EP0821163A1 (de) 1998-01-28
EP0821163A4 EP0821163A4 (de) 1998-12-16

Family

ID=13893909

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96909350A Withdrawn EP0821163A4 (de) 1995-04-12 1996-04-11 Gerät zum kontrollieren von taumelscheibenpumpe und motor

Country Status (4)

Country Link
EP (1) EP0821163A4 (de)
JP (1) JP3672046B2 (de)
KR (1) KR960038112A (de)
WO (1) WO1996032587A1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106062288A (zh) * 2014-01-30 2016-10-26 卡特彼勒Sarl 发动机和泵控制设备以及作业机器
EP2944818A4 (de) * 2013-11-20 2016-12-28 Jiangsu Hengli Hydraulic Co Ltd Leistungsregelungsvorrichtung für eine kolbenpumpe und steuerungsverfahren dafür

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103114989A (zh) * 2013-01-28 2013-05-22 上海朝田实业有限公司 一种用于节能液压泵站上的随动敏感泵

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1397084A (en) * 1971-06-12 1975-06-11 Lucas Industries Ltd Actuators for stroke control in hydraulic machines
US4248573A (en) * 1978-09-22 1981-02-03 Kabushiki Kaisha Komatsu Seisakusho Hydraulic control system for variable displacement pump
EP0549883A1 (de) * 1991-11-30 1993-07-07 Samsung Heavy Industries Co., Ltd Regelungssystem für Flüssigkeitspumpen mit veränderlichem Hub

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60113076A (ja) * 1983-11-24 1985-06-19 Daikin Ind Ltd 可変容量形液圧ポンプ
JPS63106381A (ja) * 1986-10-23 1988-05-11 Kayaba Ind Co Ltd 可変容量ポンプの出力制御装置
JPH0599124A (ja) * 1991-10-07 1993-04-20 Komatsu Ltd 可変容量型油圧ポンプの容量制御装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1397084A (en) * 1971-06-12 1975-06-11 Lucas Industries Ltd Actuators for stroke control in hydraulic machines
US4248573A (en) * 1978-09-22 1981-02-03 Kabushiki Kaisha Komatsu Seisakusho Hydraulic control system for variable displacement pump
EP0549883A1 (de) * 1991-11-30 1993-07-07 Samsung Heavy Industries Co., Ltd Regelungssystem für Flüssigkeitspumpen mit veränderlichem Hub

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9632587A1 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2944818A4 (de) * 2013-11-20 2016-12-28 Jiangsu Hengli Hydraulic Co Ltd Leistungsregelungsvorrichtung für eine kolbenpumpe und steuerungsverfahren dafür
CN106062288A (zh) * 2014-01-30 2016-10-26 卡特彼勒Sarl 发动机和泵控制设备以及作业机器

Also Published As

Publication number Publication date
WO1996032587A1 (fr) 1996-10-17
JP3672046B2 (ja) 2005-07-13
EP0821163A4 (de) 1998-12-16
KR960038112A (ko) 1996-11-21
JPH08284806A (ja) 1996-10-29

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