JP2613041B2 - Hydraulic control device - Google Patents

Hydraulic control device

Info

Publication number
JP2613041B2
JP2613041B2 JP62026147A JP2614787A JP2613041B2 JP 2613041 B2 JP2613041 B2 JP 2613041B2 JP 62026147 A JP62026147 A JP 62026147A JP 2614787 A JP2614787 A JP 2614787A JP 2613041 B2 JP2613041 B2 JP 2613041B2
Authority
JP
Japan
Prior art keywords
opening
solenoid valves
hydraulic
hydraulic pump
control
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.)
Expired - Fee Related
Application number
JP62026147A
Other languages
Japanese (ja)
Other versions
JPS63195402A (en
Inventor
秀樹 悪七
Original Assignee
株式会社小松製作所
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 株式会社小松製作所 filed Critical 株式会社小松製作所
Priority to JP62026147A priority Critical patent/JP2613041B2/en
Publication of JPS63195402A publication Critical patent/JPS63195402A/en
Application granted granted Critical
Publication of JP2613041B2 publication Critical patent/JP2613041B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2221Control of flow rate; Load sensing arrangements
    • E02F9/2232Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
    • E02F9/2235Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2221Control of flow rate; Load sensing arrangements
    • E02F9/2225Control of flow rate; Load sensing arrangements using pressure-compensating valves
    • E02F9/2228Control of flow rate; Load sensing arrangements using pressure-compensating valves including an electronic controller

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic pump control device for a vehicle such as a power shovel.

2. Description of the Related Art In a vehicle such as a power shovel, a hydraulic pump is driven by an engine, and a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder is driven by hydraulic oil obtained from the hydraulic pump. At this time, in order to effectively use the output torque of the engine, the command rotation speed given by the throttle lever and the actual rotation speed detected by the rotation speed detector, and the absorption torque of the hydraulic pump detected by the pressure detector, The discharge flow rate of the hydraulic pump is controlled so that it matches the engine output torque, so that even when the engine output is reduced, the absorption torque is adjusted to match the output decrease, so that the engine speed does not decrease. Hydraulic control devices are known.

[Problems to be Solved by the Invention] However, the opening of a solenoid valve that supplies pressure oil to a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder is controlled only by a command from an operating lever corresponding to each hydraulic actuator. Therefore, (a) when the discharge flow rate of the hydraulic pump is reduced due to the horsepower limitation of the engine, (b) when the set rotation speed of the engine is low and the swash plate angle of the hydraulic pump has already reached saturation, (c) when the engine If multiple operating levers are operated when the rotation speed of the
The discharge flow rate of the hydraulic pump is smaller than the required amount of hydraulic oil on the hydraulic actuator side, the flow distribution ratio to each hydraulic actuator changes, causing a difference in the operation feeling of each operating lever, and coupling to each hydraulic actuator There has been a problem that the working machine that has been breathed is breathed and the combined operability is reduced.

An object of the present invention is to provide a hydraulic control device that can drive a plurality of hydraulic actuators without impairing the composite operability.

Means for Solving the Problems In order to achieve the above object, the present invention provides a motor, a hydraulic pump driven by the motor, a predetermined pressure compensation characteristic, and a discharge pressure oil of the hydraulic pump. A plurality of solenoid valves respectively leading to a corresponding plurality of hydraulic actuators, a plurality of operation levers each generating a command value of the opening degree of the plurality of solenoid valves, a pressure sensor for detecting the discharge pressure of the hydraulic pump, A rotation speed detection sensor for detecting a rotation speed of the prime mover, a command value of an opening degree of the plurality of solenoid valves generated from the plurality of operation levers, a discharge pressure of the hydraulic pump detected by the pressure sensor, and the rotation speed Generating an opening control signal for controlling the opening of the plurality of solenoid valves based on the number of revolutions of the prime mover detected by a number detection sensor, and controlling the discharge flow rate of the hydraulic pump. And a control means for generating a discharge flow rate control signal for controlling the discharge flow rate of the hydraulic pump. An opening control signal for controlling the opening of the plurality of solenoid valves is set so as to be set as a balance point with the opening and to maintain the balance point.

Here, the prime mover has a predetermined horsepower limit, and the control unit, when the discharge flow rate of the hydraulic pump is reduced due to the horsepower limit of the prime mover, the plurality of An opening control signal for controlling the opening of the solenoid valve can be corrected to a small value and output.

Further, the motor is controlled to rotate with a predetermined rotation speed set in advance as a target rotation speed, and the control means corresponds to a rotation speed of the motor detected by the rotation speed detection sensor. An opening control signal for controlling the opening of the plurality of solenoid valves may be corrected and output.

Further, the control means calculates a total sum of the opening degrees of the plurality of solenoid valves based on an opening control signal for controlling the opening degrees of the plurality of solenoid valves, and the calculated value is used as a maximum discharge flow rate of the hydraulic pump. An opening control signal for controlling the opening of the plurality of solenoid valves so as not to exceed a predetermined value set correspondingly may be corrected and output.

[Operation] In the present invention, the control means sets one point of the drive pressure range of the plurality of solenoid valves as a balance point between the discharge flow rate of the hydraulic pump and the opening degrees of the plurality of solenoid valves, and maintains this balance point. An opening control signal for controlling the opening of the plurality of solenoid valves is generated.

Here, for example, when the prime mover has a predetermined horsepower limit, and the discharge flow rate of the hydraulic pump is reduced due to the horsepower limitation of the prime mover, the control unit controls the plurality of solenoid valves in accordance with the decrease. An opening control signal for controlling the opening is corrected to a small value and output.

When the prime mover is to be controlled to rotate with a predetermined rotational speed set as a target rotational speed, the control means controls a plurality of solenoid valves corresponding to the rotational speed of the prime mover detected by the rotational speed detection sensor. An opening control signal for controlling the opening is corrected and output.

Also, when multiple operation levers are operated at the same time,
The sum of the openings of the plurality of solenoid valves is calculated based on the opening control signals for controlling the openings of the plurality of solenoid valves, and the calculated value exceeds a predetermined value set corresponding to the maximum discharge flow rate of the hydraulic pump. An opening control signal for controlling the opening of a plurality of solenoid valves is corrected so as not to be output.

By such control, a plurality of hydraulic actuators can be driven without impairing the composite operability,
It is also possible to prevent a decrease in work efficiency due to a breathing of the work machine or the like.

FIG. 1 is a block diagram showing one embodiment of the present invention.
1 is an engine, 2 is a hydraulic pump driven by the engine 1, 3 is a swash plate angle operating mechanism for controlling a swash plate angle of the hydraulic pump, 4 is an unload valve, 5 is a hydraulic cylinder 6 as a first hydraulic actuator. Solenoid valve (4 port 3 position directional switching valve) for guiding hydraulic oil from hydraulic pump 2 to
Reference numeral 7 denotes a solenoid valve (4 port, 3 position direction switching valve) for guiding hydraulic oil from the hydraulic pump 2 to a hydraulic motor 8 as a second hydraulic actuator, and 9 denotes a first valve for instructing the opening of the solenoid valve 5. An operating lever, 10 a second operating lever for instructing the opening of the solenoid valve 7, 11 a rotational speed detector for detecting the engine rotational speed, 12 a pressure detector for detecting the discharge pressure of the hydraulic pump 2, 13 Is a control device.

The control device 13 controls the command rotation speed given by the throttle lever and the like, the actual rotation speed detected by the rotation speed detector 11, and the absorption torque of the hydraulic pump detected based on the detection signal of the pressure detector 12, as in the conventional case. The discharge flow rate of the hydraulic pump 2 is determined so that the output torque of the engine 1 matches, and the swash plate angle of the hydraulic pump 2 is controlled via the swash plate angle operation mechanism 3.

On the other hand, the control device 13 detects a command opening signal from the operating levers 9, 10, and controls the opening of the solenoid valves 5, 6 to the commanded opening. As a result, the hydraulic cylinder 6 and the hydraulic motor 8 are supplied with hydraulic oil in an amount corresponding to the command opening of the operating levers 9 and 10 to operate.

Here, the solenoid valves 5 and 7 are controlled by the second control signal I for the opening degree.
It has flow control characteristics as shown in the figure, and the control signals I = I 1 , I = I 2 , and I = I 3 respectively under the condition that the pressure difference ΔP between the inlet and the outlet of the pressure oil becomes ΔP 1. The corresponding flow rate Q 1 ,
It is configured to obtain 2 and 3 .

The control device 13 utilizes such a flow control characteristic, and when the discharge flow rate of the hydraulic pump 2 is reduced due to the horsepower limitation of the engine 1, or when the set rotation speed of the engine 1 is low, the swash plate angle of the hydraulic pump 2 becomes saturated. When the discharge flow rate of the hydraulic pump 2 is less than the required flow rate of the hydraulic cylinder 6 and the hydraulic motor 8 as in the case where the hydraulic cylinder 6 and the hydraulic motor 8 are simultaneously driven, Hydraulic pump 2
The opening degree of the solenoid valves 5 and 7 is reduced so as to match the discharge flow rate.

That is, FIG. 3 is a diagram showing the relationship between the discharge flow rate Q of the hydraulic pump 2 and the discharge pressure P. In the case where the discharge flow rate Q 0 is to be obtained by operating the operation levers 9 and 10, the discharge pressure P if There long as a P = P 1, the discharge flow rate by the output control characteristic of the engine 1 indicated by a one-dot chain line is lowered to Q 1. Therefore, the value before the discharge flow rate is reduced is Q
0 , the value after the drop is Q 1 , and the current opening control signal of the solenoid valve 5 (or 7) is I, and I ′ = I × Q 1 / Q 0 (1) The degree control signal I 'is obtained, and the degrees of opening of the solenoid valves 5 and 7 are corrected so as to match this. This correction of the opening is simultaneously performed for all the solenoid valves (5, 7) connected to the output of the hydraulic pump 2.

In addition, when the swash plate angle of the hydraulic pump 2 has already reached saturation, the discharge flow rate Q does not change even if the operating levers 9 and 10 are operated. The maximum value is Qmax, and the opening command signal of the i-th (i = 1, 2,...) Solenoid valve currently indicated by the operation lever is
Assuming that Ii, the opening control signal Ii 'at the time of swash plate angle saturation is obtained by Ii' = Qmax.Ii / .SIGMA.Ii. The opening of the solenoid valve is controlled in such a manner as to be performed.

Therefore, the total sum of the opening degrees of all the solenoid valves (5, 7) is limited in accordance with the maximum value Qmax of the discharge flow rate of the hydraulic pump 2. In this case, the change speed of the hydraulic actuator can be easily controlled by considering the coupling coefficient aij for each hydraulic actuator as shown in the following equation (3).

Ii ′ = Qmax (Σaij · Qi) / Σ (Σaij · Qi) (3) On the other hand, the discharge flow rate Q of the hydraulic pump 2 is represented by q as the discharge flow rate per one rotation and Es as the rotation speed of the engine 1. Then, it is expressed by Q = q · Es. Further, the discharge flow rate q per rotation has a relationship of a function value q = f (S) of the stroke amount S of the operation lever as shown in FIG. 4 (a). Also, q and hydraulic pump 2
And the swash plate angle control signal Ip, as shown in FIG. 4 (b), is a function value of Ip q = f (Ip). Therefore, even if the stroke amount S of the operation lever is increased, a required discharge flow rate cannot be obtained if the engine speed is small. Therefore,
Controller 13 secures a differential pressure [Delta] P 1 of the inlet and outlet hydraulic pump 2, and the degree of opening of the solenoid valve the current discharge flow rate, i.e. the solenoid valve so as to correspond to the current engine speed (5,7 )
Control the opening degree. Specifically, I = fv -1 {f (s) · Es, ΔP 1 } (4) is used to determine the solenoid valve opening control signal I corresponding to the current engine speed to open the solenoid valve. Control the degree. However,
fv represents the relationship between the discharge flow rate and the pressure loss with respect to the input signal of the solenoid valve.

Therefore, when the discharge flow rate of the hydraulic pump is reduced due to the horsepower limitation of the engine, when the set rotation speed of the engine is low and the swash plate angle of the hydraulic pump reaches saturation, or when a plurality of hydraulic actuators are simultaneously driven, In each hydraulic actuator, the amount of hydraulic oil is reduced at a ratio corresponding to the load distribution, so that the composite operability is not impaired.

Further, in any of the embodiments, since the changing speed of the hydraulic actuator can be individually adjusted by giving the opening control signal of the solenoid valve, there is an advantage that the changing speed of the hydraulic actuator can be easily balanced. is there.

Since the discharge flow rate of the hydraulic pump 2 can be estimated based on the control signal of the swash plate angle or the actual rotation speed of the engine 1, there is no need to provide a discharge flow rate detector.

[Effects of the Invention] As described above, according to the present invention, it is possible to drive a plurality of hydraulic actuators without impairing the combined operability thereof, and to prevent a decrease in work efficiency due to breathing of a work machine or the like. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a characteristic diagram showing flow control characteristics of a solenoid valve, FIG. 3 is a diagram showing a relationship between a discharge flow rate and a discharge pressure of a hydraulic pump, FIG. The figure shows the relationship between the discharge flow per rotation of the hydraulic pump, the stroke of the operating lever, and the swash plate angle control signal. 1 ... Engine, 2 ... Hydraulic pump, 3 ... Swash plate angle, operating mechanism, 5,7 ... Solenoid valve, 6 ... Hydraulic cylinder, 8 ...
Hydraulic motor, 9,10… Operation lever, 11… Rotation detector, 12… Pressure detector, 13… Control device.

Claims (4)

    (57) [Claims]
  1. A motor, a hydraulic pump driven by the motor, a plurality of solenoid valves having a predetermined pressure compensation characteristic, and guiding discharge hydraulic oil of the hydraulic pump to a plurality of hydraulic actuators respectively corresponding to the motor; A plurality of operation levers each generating a command value of an opening degree of the plurality of solenoid valves; a pressure sensor detecting a discharge pressure of the hydraulic pump; a rotation speed detection sensor detecting a rotation speed of the prime mover; The plurality of solenoid valves based on a command value of the opening degree of the plurality of solenoid valves generated from the operation lever and the discharge pressure of the hydraulic pump detected by the pressure sensor and the rotation speed of the prime mover detected by the rotation speed detection sensor. Control means for generating an opening control signal for controlling the opening of the solenoid valve and generating a discharge flow control signal for controlling the discharge flow of the hydraulic pump. In the hydraulic control device, the control unit may set one point of a driving pressure range of the plurality of solenoid valves as a balance point between a discharge flow rate of the hydraulic pump and an opening degree of the plurality of solenoid valves, and maintain this balance point. A hydraulic control device for generating an opening control signal for controlling the opening of the plurality of solenoid valves.
  2. 2. The motor has a predetermined horsepower limit, and the control means, when the discharge flow rate of the hydraulic pump is reduced due to the horsepower limitation of the motor, corresponds to the reduced amount. 2. The hydraulic control device according to claim 1, wherein an opening control signal for controlling the opening of the plurality of solenoid valves is corrected to a small value and output.
  3. 3. The rotation of the prime mover is controlled by using a preset rotation speed as a target rotation speed, and the control means controls the rotation speed of the prime mover detected by the rotation speed detection sensor. 2. The hydraulic control apparatus according to claim 1, wherein an opening control signal for controlling the opening of the plurality of solenoid valves is corrected and output.
  4. 4. The control means calculates a total sum of the openings of the plurality of solenoid valves based on an opening control signal for controlling the openings of the plurality of solenoid valves, and the calculated value is a maximum value of the hydraulic pump. 2. The method according to claim 1, wherein an opening control signal for controlling the opening of the plurality of solenoid valves is corrected and output so as not to exceed a predetermined value set in accordance with the discharge flow rate. Hydraulic control device.
JP62026147A 1987-02-06 1987-02-06 Hydraulic control device Expired - Fee Related JP2613041B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62026147A JP2613041B2 (en) 1987-02-06 1987-02-06 Hydraulic control device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62026147A JP2613041B2 (en) 1987-02-06 1987-02-06 Hydraulic control device

Publications (2)

Publication Number Publication Date
JPS63195402A JPS63195402A (en) 1988-08-12
JP2613041B2 true JP2613041B2 (en) 1997-05-21

Family

ID=12185431

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62026147A Expired - Fee Related JP2613041B2 (en) 1987-02-06 1987-02-06 Hydraulic control device

Country Status (1)

Country Link
JP (1) JP2613041B2 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7121189B2 (en) 2004-09-29 2006-10-17 Caterpillar Inc. Electronically and hydraulically-actuated drain value
US7146808B2 (en) 2004-10-29 2006-12-12 Caterpillar Inc Hydraulic system having priority based flow control
US7204084B2 (en) 2004-10-29 2007-04-17 Caterpillar Inc Hydraulic system having a pressure compensator
US7204185B2 (en) 2005-04-29 2007-04-17 Caterpillar Inc Hydraulic system having a pressure compensator
US7210396B2 (en) 2005-08-31 2007-05-01 Caterpillar Inc Valve having a hysteretic filtered actuation command
US7243493B2 (en) 2005-04-29 2007-07-17 Caterpillar Inc Valve gradually communicating a pressure signal
US7302797B2 (en) 2005-05-31 2007-12-04 Caterpillar Inc. Hydraulic system having a post-pressure compensator
US7320216B2 (en) 2005-10-31 2008-01-22 Caterpillar Inc. Hydraulic system having pressure compensated bypass
US7331175B2 (en) 2005-08-31 2008-02-19 Caterpillar Inc. Hydraulic system having area controlled bypass
US7441404B2 (en) 2004-11-30 2008-10-28 Caterpillar Inc. Configurable hydraulic control system
US7614336B2 (en) 2005-09-30 2009-11-10 Caterpillar Inc. Hydraulic system having augmented pressure compensation
US7621211B2 (en) 2007-05-31 2009-11-24 Caterpillar Inc. Force feedback poppet valve having an integrated pressure compensator

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2677803B2 (en) * 1987-11-25 1997-11-17 日立建機株式会社 Hydraulic drive
JPH082189Y2 (en) * 1988-09-26 1996-01-24 株式会社小松製作所 Arm operation circuit device
JPH0269509U (en) * 1988-11-17 1990-05-25
JP2520771B2 (en) * 1990-07-18 1996-07-31 小松メック株式会社 Control method and apparatus for loading work vehicle
US7260931B2 (en) * 2005-11-28 2007-08-28 Caterpillar Inc. Multi-actuator pressure-based flow control system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5865304A (en) * 1981-10-09 1983-04-19 Japan Steel Works Ltd:The Oil pressure control apparatus
DE3321483A1 (en) * 1983-06-14 1984-12-20 Linde Ag Hydraulic device with one pump and at least two of these inacted consumers of hydraulic energy
JPS60208605A (en) * 1984-03-31 1985-10-21 Ishikawajima Harima Heavy Ind Co Ltd On-deck machinery control equipment for ship

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7121189B2 (en) 2004-09-29 2006-10-17 Caterpillar Inc. Electronically and hydraulically-actuated drain value
US7146808B2 (en) 2004-10-29 2006-12-12 Caterpillar Inc Hydraulic system having priority based flow control
US7204084B2 (en) 2004-10-29 2007-04-17 Caterpillar Inc Hydraulic system having a pressure compensator
US7441404B2 (en) 2004-11-30 2008-10-28 Caterpillar Inc. Configurable hydraulic control system
US7243493B2 (en) 2005-04-29 2007-07-17 Caterpillar Inc Valve gradually communicating a pressure signal
US7204185B2 (en) 2005-04-29 2007-04-17 Caterpillar Inc Hydraulic system having a pressure compensator
US7302797B2 (en) 2005-05-31 2007-12-04 Caterpillar Inc. Hydraulic system having a post-pressure compensator
US7210396B2 (en) 2005-08-31 2007-05-01 Caterpillar Inc Valve having a hysteretic filtered actuation command
US7331175B2 (en) 2005-08-31 2008-02-19 Caterpillar Inc. Hydraulic system having area controlled bypass
US7614336B2 (en) 2005-09-30 2009-11-10 Caterpillar Inc. Hydraulic system having augmented pressure compensation
US7320216B2 (en) 2005-10-31 2008-01-22 Caterpillar Inc. Hydraulic system having pressure compensated bypass
US7621211B2 (en) 2007-05-31 2009-11-24 Caterpillar Inc. Force feedback poppet valve having an integrated pressure compensator

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Publication number Publication date
JPS63195402A (en) 1988-08-12

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