JP2013023034A - Hydraulic working machine having generator using hydraulic flow energy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy-saving technology for reducing wasteful use of hydraulic energy caused by the circulation of a hydraulic oil between a hydraulic pump and a tank.SOLUTION: This hydraulic working machine such as a tractor includes a hydraulic circuit, a generator using hydraulic flow energy 8 arranged in a discharge oil passage for discharging the hydraulic oil of this hydraulic circuit to the tank 90 and having moving blades 81 rotating by a hydraulic flow, and a charge-discharge control section 70 for charging electric power output from the generator 8 to a battery 7. The generator using the hydraulic flow energy 8 selects a generator 8a when the hydraulic oil is in a high pressure, and selects a generator 8b in a low pressure. Further, a generator 8c branches off the oil in an oil passage into a high pressure passage or a low pressure passage, by arranging a pressure sensitive branch valve.

Description

  The present invention relates to a hydraulic work machine including a hydraulic circuit that supplies hydraulic pressure generated by a hydraulic pump to various hydraulic devices.

  In such a hydraulic circuit, a complicated circuit including a hydraulic valve is constructed to control the supply of hydraulic oil having a predetermined hydraulic pressure created by a hydraulic pump so that the incorporated hydraulic equipment performs various operations. However, the supplied hydraulic oil is finally returned to the tank and pumped up again by the hydraulic pump. Depending on the hydraulic circuit, when the control valve is in the neutral position, the hydraulic fluid sent from the hydraulic pump is returned to the tank through the relief valve. However, the relief pressure is still applied to the hydraulic pump, and the hydraulic energy generated by the hydraulic pump remains. There is a lot of wasted consumption. Further, when the unload circuit is used, the hydraulic pump is unloaded, but the wasteful consumption of hydraulic energy due to the circulation of the hydraulic oil between the hydraulic pump and the tank remains unchanged.

In addition, in order to effectively use unused hydroelectric energy in a familiar living environment, a generator that reduces installation space, so-called micro hydroelectric power generation, has started to think about in order to effectively use unused hydroelectric energy in a familiar living environment. It has been. For example, in Patent Document 1, a faucet that is installed in a toilet or a washstand, opens a solenoid valve with a sensor, a switch, or the like to discharge water, and generates electric power by the water flow at the time of discharging water to drive the solenoid valve. An apparatus is described. Here, a faucet hydroelectric generator generates electricity using the flow of water supply in order to supply power to the electrical equipment incorporated in the faucet device.
However, no consideration is given to the effective use of the hydraulic energy of the hydraulic flow in the hydraulic circuit.

Japanese Patent Laying-Open No. 2011-12515 (FIG. 1)

  From the above situation, an energy saving technique for reducing waste of hydraulic energy due to the circulation of hydraulic oil between the hydraulic pump and the tank is desired.

The hydraulic working machine according to the present invention is characterized in that a hydraulic circuit, a hydraulic flow generator having a moving blade rotated by a hydraulic flow, provided in a discharge oil passage for discharging hydraulic oil of the hydraulic circuit to a tank, A charge / discharge control unit that charges the battery with the electric power output from the generator.
The hydraulic oil flowing in the hydraulic circuit is finally discharged to a tank (hydraulic oil tank), pumped up from the same place by a hydraulic pump or the like, and flows again through the hydraulic circuit as hydraulic oil having a required hydraulic pressure. Therefore, the flow energy (kinetic energy) and potential energy of the hydraulic oil discharged to the tank are wasted. According to the above configuration of the present invention, the moving blades of the hydraulic flow generator are rotated by the hydraulic flow so as to utilize the energy of the hydraulic oil discharged to the tank. By performing necessary conversion processing on the electric power generated based on this rotation, the electric power becomes charging electric power for the battery. Thereby, the energy of the hydraulic oil discharged to the tank, which has not been used so far, can be recovered in the form of electric power, contributing to energy saving.

  There are high-pressure hydraulic oil that still has a considerably high hydraulic pressure value and low-pressure hydraulic oil that has almost decreased to atmospheric pressure. Since the kinetic energy differs between the high-pressure hydraulic oil and the low-pressure hydraulic oil, it is more effective to adapt the form of the hydraulic flow generator to each in order to use the hydraulic flow more efficiently. For this reason, in one preferred embodiment of the present invention, the generator has a low-pressure flow generator mounted in a low-pressure oil passage through which low-pressure hydraulic oil flows, and high-pressure hydraulic oil flows through the low-pressure oil passage. A high-pressure flow generator mounted on the high-pressure oil passage, and the moving blades of the low-pressure flow generator are configured to rotate with a working oil flow using gravity of the hydraulic oil, and the high-pressure flow generator operates. A housing portion that functions as an oil circulation oil passage is provided, and the moving blades of the high-pressure generator are configured to rotate by hydraulic oil that flows through the housing portion. In this configuration, in a low-pressure flow generator in which a low-pressure hydraulic flow flows, like a turbine, a rotor blade is rotated in a form that mainly uses potential energy, and in a high-pressure flow generator in which a high-pressure hydraulic flow flows, like a turbine. The rotor blades are rotated in a form that utilizes the kinetic energy of the hydraulic flow that mainly flows. Thereby, the energy of the low-pressure or high-pressure hydraulic oil can be recovered as electric power as efficiently as possible.

  There are various circuit forms in the hydraulic circuit, and depending on the discharge oil passage for discharging the hydraulic oil to the tank, a high pressure flow or a low pressure flow flows depending on the operating state of the hydraulic equipment of the hydraulic circuit. In order to efficiently recover the hydraulic flow energy in such an exhaust oil passage, in one embodiment of the present invention, the hydraulic pressure is branched to the first branch oil passage with a hydraulic pressure equal to or higher than a predetermined hydraulic pressure, and the predetermined hydraulic pressure is increased. A pressure-sensitive branch valve that branches to the second branch oil passage with a lower hydraulic pressure is provided in the discharge oil passage, the high-pressure flow generator is attached to the first branch oil passage, and the low-pressure flow is supplied to the second branch oil passage. A generator is installed.

It is a schematic diagram illustrating the basic principle of hydraulic flow power generation adopted in the present invention. 1 is an external view of a tractor equipped with a hydraulic circuit as an example of a hydraulic working machine according to the present invention. FIG. 3 is a power system diagram including hydraulic pressure in the tractor of FIG. 2. It is a hydraulic circuit diagram including a hydraulic fluid generator.

Before describing specific embodiments of the present invention, the basic principle of hydraulic flow power generation employed in a hydraulic working machine according to the present invention will be described with reference to the schematic diagram of FIG.
In FIG. 1, a hydraulic fluid generator 8 is interposed in a discharge oil passage connected to a tank 90 from a group of hydraulic devices included in the hydraulic circuit. The hydraulic flow generator 8 includes a moving blade 81 that is rotated by a hydraulic flow that flows through the discharged oil passage 9. In FIG. 1, three types of generators 8, that is, an A type generator 8 a, a B type generator 8 b, and a C type generator 8 c are shown. The word 8 is used.

The A-type generator 8a is mounted on the oil passage 9 through which high-pressure hydraulic oil flows, and the moving blade 81 is surrounded by a small gap along the flow direction by the housing portion 80a. Thus, the moving blade 81 is rotated while flowing through the moving blade 81 with a high-pressure flow.
The B type generator 8b is mounted on the oil passage 9 through which low-pressure hydraulic oil flows, and the moving blade 81 is surrounded by a housing portion 80b with a large gap along the flow direction or the moving blade. 81 is not enclosed by the housing part 80b. That is, it has a structure in which the moving blade 81 is rotated by flowing hydraulic oil flowing through the difference in gravity (height difference) over the moving blade 81 like a water wheel.
The C-type generator 8c is a combination of an A-type generator 8a and a B-type generator 8b, and is attached to an oil passage 9 having a period during which high-pressure hydraulic oil flows and a period during which low-pressure hydraulic oil flows. . That is, a first branch oil passage for flowing a high hydraulic flow and a second branch oil passage for flowing a low hydraulic flow are formed in the C-type generator 8c as a housing portion 80c. A generator 8a is interposed, and a B-type generator 8b is interposed in the second branch oil passage. At the branch point of the first branch oil passage and the second branch oil passage, pressure sensitivity is branched to the first branch oil passage with a hydraulic pressure equal to or higher than a predetermined hydraulic pressure of the hydraulic flow and branched to the second branch oil passage with a hydraulic pressure lower than the predetermined hydraulic pressure. A branch valve is provided.

  Although only schematically shown in FIG. 1, the generator 8 holds housing portions 80 a, 80 b, 80 c formed in a cylindrical shape, a rotor 82 having a common axis with the moving blade 81, and a stator 83. A holding bracket is provided. The electric power generated by the cooperative action of the rotor 82 and the stator 83 that rotate in conjunction with the rotation of the moving blade 81 is used for charging the battery 7 by the charge / discharge control unit 70 including the charging unit and the discharging unit.

  A hydraulic pump 91 that pumps up the hydraulic oil finally returned to the tank 90 and supplies hydraulic pressure to the hydraulic equipment group receives rotational power from an output shaft of an internal combustion engine or an electric motor used as a power source of the hydraulic work machine. receive.

  A tractor which is one embodiment of the hydraulic working machine having the basic principle of hydraulic flow power generation described above will be described below. FIG. 2 is an external view of a tractor equipped with a hydraulic circuit having a hydraulic flow power generation function. FIG. 3 is a power system diagram including a hydraulic circuit 60 in the tractor.

  In this tractor, the power from the output shaft 30 of the diesel-type engine 1 is a hydrostatic continuously variable transmission (hereinafter abbreviated as HST) 2 that is an example of a continuously variable transmission, and a plurality of HST transmission powers. Here, it is transmitted to the transmission output shaft 31 via the auxiliary transmission 32 that shifts in two steps (high and low), and finally the driving wheel (front wheel and / or rear wheel) 3 is rotated. Further, the power from the output shaft 30 of the engine 1 is transmitted to the external work machine 4 such as a tillage work machine equipped on the tractor via the PTO transmission system 40. In the PTO transmission system 40, the PTO transmission system 40

  As is well known, the HST 2 includes a variable displacement hydraulic pump and a hydraulic motor configured in an axial plunger type. The hydraulic pump is rotationally driven by the output shaft 30 of the engine 1. By changing the swash plate angle of the swash plate in the hydraulic pump, the discharge direction and the discharge amount of the discharged pressure oil are changed, and the rotation of the output shaft of the hydraulic motor that receives the pressure oil rotates in the forward direction (forward). Alternatively, the speed is changed steplessly in the reverse direction (reverse).

  As shown in FIG. 4, the hydraulic circuit in this tractor includes an HST hydraulic circuit 61, a PTO hydraulic circuit 62, a work implement hydraulic circuit 64, a pressure adjustment hydraulic circuit 65, a power steering hydraulic circuit 66, and further omitted in FIG. However, an auxiliary transmission hydraulic circuit 63 is included.

The hydraulic pump and hydraulic motor of HST 2 are incorporated in the HST hydraulic circuit 61, and the swash plate angle of the hydraulic pump is changed by the swash plate control hydraulic device of the HST hydraulic circuit 61. The swash plate control hydraulic equipment includes hydraulic equipment such as a cylinder and an electromagnetic control valve.
The PTO hydraulic circuit 62 is turned on and off by supplying and discharging hydraulic oil to and from a piston incorporated in the PTO clutch 41. The auxiliary transmission hydraulic circuit 63 has a configuration similar to that of the PTO hydraulic circuit 62, and selectively generates a high speed stage or a low speed stage of the high / low auxiliary transmission device 32 by supplying and discharging hydraulic oil to / from the piston of the auxiliary transmission clutch. .

Only the hydraulic equipment for operating the hydraulic cylinder is shown here as the working equipment hydraulic circuit 64, but the external working machine 4 incorporating a number of hydraulic equipment such as a plurality of hydraulic cylinders and hydraulic motors is mounted. In this case, the hydraulic circuit is considerably complicated and a large amount of hydraulic fluid is supplied and discharged.
The pressure adjustment hydraulic circuit 65 is a circuit that performs pressure adjustment in the hydraulic circuit, and the relief valve is activated in response to the generation of the hydraulic pressure exceeding the predetermined pressure, and the hydraulic oil in the hydraulic circuit is set to the predetermined pressure by returning the hydraulic oil to the tank. maintain.
The power steering hydraulic circuit 66 operates the power steering cylinder and assist hydraulic motor of the steering operation mechanism.

  In this hydraulic circuit 60, except for the HST hydraulic circuit 61, hydraulic pressure is supplied by a hydraulic pump 91 driven by the output shaft 30 of the engine 1. In FIG. 4, two hydraulic pumps 91 are connected to the output shaft 30. Since the capacity of the hydraulic pump 91 is determined based on the maximum required amount of hydraulic pressure required by the hydraulic circuit 60, a considerable surplus is present in the hydraulic oil supplied to the hydraulic circuit 60 by the hydraulic pump 91 during normal operation. Hydraulic flow will be included. At least a part of the energy of the surplus hydraulic flow is recovered in the form of electric power by the hydraulic flow generator 8.

  The hydraulic equipment group included in the hydraulic circuit 60 of the tractor including the various hydraulic circuits described above is controlled by the hydraulic control means 6. The vehicle control controller 5A and the external work machine control controller 5B give a control command to the hydraulic pressure control means 6.

[Another embodiment]
(1) In the above-described embodiment, the hydraulic flow generator 8 is provided for each oil discharge path to the tank 90. However, some or all of the oil discharge paths are integrated, and the integrated oil discharge is performed. You may employ | adopt the structure which provides the hydraulic flow type generator 8 in a path.
(2) As the form of the hydraulic flow generator 8, various forms used for micro hydroelectric power generation and the like other than those shown in the above-described embodiments can be used.
(3) In the above-described embodiment, the HST2 is adopted as the continuously variable transmission. However, instead of this, the hydraulic flow according to the present invention is also applied to a hydraulic transmission such as an HMT (Hydraulic Mechanical Transmission). Power generation can be applied.
(4) Examples of the hydraulic working machine to which the present invention can be applied include, in relation to vehicles, other than a tractor, a rice transplanter, a combine, a lawn mower, a civil engineering / architectural work machine, an off-road car such as a buggy, etc. The present invention can also be applied to a stationary hydraulic working machine.

  The present invention can be applied to all hydraulic work machines having an oil passage for discharging hydraulic oil to a tank.

60: Hydraulic circuit 7: Battery 70: Charge / discharge control unit (charge control unit)
8: Hydraulic flow type generator 8a: High pressure flow generator 8b: Low pressure flow generator 80a: Housing portion 80d: Pressure sensitive branch valve 81: Moving blade 9: Oil passage (discharge oil passage)
90: Hydraulic oil tank (tank)

Claims (3)

A hydraulic circuit, a hydraulic flow generator having a moving blade rotated by a hydraulic flow, provided in a discharge oil passage for discharging hydraulic oil of the hydraulic circuit to a tank, and electric power output from the generator to a battery A hydraulic working machine including a charge / discharge control unit for charging. The generator includes a low-pressure flow generator attached to a low-pressure oil passage through which low-pressure hydraulic oil flows, and a high-pressure flow generator attached to a high-pressure oil passage through which high-pressure hydraulic oil flows from the low-pressure oil passage, The moving blades of the low-pressure flow generator are configured to rotate by a gravity flow of hydraulic oil, and the high-pressure flow generator includes a housing portion that functions as a hydraulic oil distribution oil passage. The hydraulic working machine according to claim 1, wherein the blade is configured to rotate by hydraulic oil flowing through the housing portion. A pressure-sensitive branch valve that branches to the first branch oil passage with a hydraulic pressure equal to or higher than a predetermined hydraulic pressure of the hydraulic flow and branches to the second branch oil passage with a hydraulic pressure lower than the predetermined hydraulic pressure is provided in the discharge oil passage, and the first branch oil The hydraulic working machine according to claim 2, wherein the high-pressure flow generator is attached to a road, and the low-pressure flow generator is attached to the second branch oil passage.

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