KR101989627B1

KR101989627B1 - Hybrid construction machinery

Info

Publication number: KR101989627B1
Application number: KR1020120151958A
Authority: KR
Inventors: 장달식
Original assignee: 두산인프라코어 주식회사
Priority date: 2012-12-24
Filing date: 2012-12-24
Publication date: 2019-06-14
Also published as: KR20140083119A

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid construction equipment capable of recovering and recovering abandoned hydraulic pressure, and more particularly, to a hybrid construction equipment capable of regenerating hydraulic pressure without changing a main control valve for distributing hydraulic pressure, And more particularly to a hybrid construction equipment that can be supplied adaptively.

Description

[0001] Hybrid construction machinery [

Recently, in the field of automotive technology, hybrid technology has been adopted in construction equipment as well as in the case of energy stored in an electric energy storage device such as a battery and then recycled and recycled.

The hybrid construction equipment converts the kinetic energy of the hydraulic fluid drained into the tank into electric energy when the swing motor is stopped and stores the converted kinetic energy of the hydraulic fluid drained when the boom descends.

However, since construction equipment is driven by hydraulic power, unlike automobiles, it is inefficient itself by converting hydraulic energy (kinetic energy) into electric energy and then converting it into hydraulic energy and supplying it to construction equipment. Therefore, it is ideal to store the hydraulic energy and immediately use the hydraulic energy.

However, in order to use hydraulic energy directly, it is difficult to guarantee durability when storing high-pressure hydraulic energy, and it is difficult to implement such a device. Further, unless the hydraulic energy is stored so that it is supplied along the direction of movement of the necessary hydraulic pressure, the hydraulic energy is merely stored, not recycled.

In the US patent application US2009-0217653, as shown in Fig. 1, the hydraulic pressure supplied from the pump 14 is supplied to the pressure swing motor 11 through the IMV (Independent Metering Valve) 17 to turn the upper revolving body of the excavator , And proposed a technique of regenerating the discarded hydraulic pressure.

The regeneration is performed such that the hydraulic pressure abandoned through the first motor supply line 19 and the second motor supply line 21 is filled in the accumulator 88 via the selector valve 80, the modulation valve 82 and the filling valve 85 And the hydraulic energy thus stored is supplied to the pressure swing motor 11 through a direction opposite to the above filling direction.

However, in the conventional technique as described above, the accumulator 88 is connected only to the pressure swing motor 11 through the selector valve 80. [ Therefore, only the hydraulic energy discarded in the pressure swing motor 11 is recovered, and the regenerated hydraulic energy is also provided to the pressure swing motor 11 only. Thus, the number of cases where it is applicable is limited to one.

IMV 17 having a plurality of variable restrictors such as CTs 62 and 63 and PCs 58 and 59 is used to regenerate the hydraulic energy. In this case, There is a problem that it is necessary to replace the IMV 17 with the IMV 17.

In addition, since it is inevitable to change the design of the entire hydraulic system so as to include the IMV 17 and the selector valve 80, it is practically impossible to apply such a regeneration system to existing construction equipment.

In addition, for example, a construction equipment such as an excavator should distribute the hydraulic pressure to various actuators, such as a front work station made up of a boom / arm / bucket or other field work, as well as a pressure swing motor 11 for turning the upper revolving body . Therefore, there is a problem that a main control valve (not shown) must be additionally provided.

In order to regenerate the hydraulic energy, the IMV 17 must be controlled, and at the same time, the main control valve for distributing the hydraulic pressure to the pressure swing motor 11 and the actuator, There is a problem that control of the main control valve is more difficult for interlocking the main control valve.

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems, and it is an object of the present invention to provide a hydraulic control apparatus capable of regenerating the hydraulic pressure without changing the main control valve for distributing the hydraulic pressure in recovering and regenerating the discarded hydraulic pressure, To the hybrid construction equipment.

To this end, the hybrid construction equipment according to the present invention comprises a main pump; A swing motor for receiving hydraulic fluid supplied from the main pump through a main control valve; An accumulator for storing operating fluid discarded by the swing motor and supplying the operating fluid during regeneration; A charge selection valve for controlling the hydraulic fluid flowing into and out of the accumulator; A first main regeneration valve that is regulated in a closing direction when the hydraulic fluid discarded from the swing motor is stored in the accumulator and is regulated in a direction to open when the hydraulic fluid discarded from the swing motor is recovered to an input port of the main control valve and regenerated; And a controller for controlling the main pump, the fill-selection valve, and the first main regeneration valve according to a work load.

At this time, the first main regeneration valve is preferably installed between the charge selection valve and the input port of the main control valve.

The controller may further include a pressure sensor for sensing a filling amount of the hydraulic fluid filled in the accumulator, wherein the controller receives information on the filling amount from the pressure sensor, .

A first check valve provided on the first line and a second check valve provided on the other line of the swing motor for connecting the other port of the swing motor to the fill- A second check valve provided in the second line, a third line connected between the fill selection valve and the first main regeneration valve, and a third check valve provided in the third line, .

It is further preferred that the boom actuator further comprises a boom actuator for operating a boom of the work device, wherein the hydraulic drain port of the boom actuator is connected to the fill selector valve via a fourth line.

In addition, it is preferable that the drain port of the hydraulic oil of the boom actuator is commonly connected to the storage tank through the second main regeneration valve.

In the present invention as described above, the first main regeneration valve is provided at the input port of the main control valve to regulate the regeneration of the hydraulic energy, so that regeneration of the discarded hydraulic pressure can be performed without changing the main control valve that distributes the hydraulic pressure to various motors or actuators. .

In addition, since the existing main control valve is used as it is, it is possible to adapt regenerated hydraulic pressure to various motors and actuators adaptively, without having to replace expensive valves such as IMV or change the design of the hydraulic system.

1 is a view showing a hydraulic system of a hybrid construction equipment according to the prior art.
2 is a diagram illustrating a hydraulic system of a hybrid construction equipment according to an embodiment of the present invention.
3 is a diagram illustrating a hydraulic system of a hybrid construction equipment according to another embodiment of the present invention.

Hereinafter, a hybrid construction equipment according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, an excavator will be described as an example of a typical construction equipment, but the present invention is not limited thereto, and it is obvious that the present invention can be applied to other equipment as long as it includes an upper revolving structure.

As shown in FIG. 2, the hybrid construction equipment according to the present invention is a hybrid excavator and includes a main pump P, a main control valve MCV, a swing motor S_M, CHV1 and CHV2, relief valves RV1 and RV2, an actuator control valve A_V and a first actuator ACT1.

The above configurations are included in the hydraulic system of a general excavator. The hydraulic pressure supplied from the main pump P is selected and distributed through the main control valve MCV and supplied to one port or the other port of the swing motor S_M.

As is well known, the main control valve (MCV) has a variable orifice in the interior thereof to control the flow rate (or the hydraulic pressure), thereby freely controlling the supply selection and distribution amount of the hydraulic pressure.

Therefore, the hydraulic pressure supplied through the A2 port of the main control valve MCV is supplied to one port of the swing motor S_M and then flows into the B2 port of the main control valve MCV, thereby driving the swing motor S_M to one side .

The hydraulic pressure supplied through the B2 port of the main control valve MCV is supplied to the other port of the swing motor S_M and then flows into the A2 port of the main control valve MCV.

The motor check valves CHV1 and CHV2 prevent the operation oil supplied to the swing motor S_M from flowing backward and the operation oil corresponding to the excess oil pressure is recovered to the tank through the relief valves RV1 and RV2.

The swivel motor S_M is driven in one direction or the other direction and the upper swivel body of the excavator connected to the swivel motor S_M is turned in one direction (for example, clockwise) or the other direction (for example, counterclockwise).

Further, the hydraulic pressure supplied from the main pump P is supplied to the actuator control valve A_V via the main control valve MCV. The actuator control valve A_V is connected to both ports of the first actuator ACT1 to linearly reciprocate the cylinder rod of the first actuator ACT1 to one side or the other side.

In the meantime, the present invention stores the hydraulic energy generated when the swing motor S_M is started and stopped, and supplies the hydraulic energy to the accumulator 110, the accumulator 110, the first actuator ACT1, And further includes a fill selection valve 120 and a first main regeneration valve 130. It also includes a controller C for controlling the main pump P, the fill selector valve 120 and the first main regeneration valve 130.

The accumulator 110 temporarily stores the operating oil discarded by the swing motor S_M, and supplies it to the accumulator 110 during the regeneration. That is, the hydraulic fluid, which is hydraulic energy, is received and stored through the fill selector valve 120 during filling, and supplied to the swing motor S_M or the first actuator ACT1 via the main control valve MCV during recycling.

The accumulator 110 is also provided with a pressure sensor 110a. The pressure sensor 110a senses the filling amount of the operating fluid filled in the accumulator 110 and provides the sensed filling amount information (i.e., pressure) to the controller C. [ The controller C controls the main pump P, the fill selection valve 120 and the first main regeneration valve 130 based on this information.

The fill selection valve 120 is installed in the accumulator 110 to intermittently control the flow rate of hydraulic oil flowing into and out of the accumulator 110.

For example, the fill selection valve 120 is composed of two check valves arranged in opposite directions to each other. Therefore, when the fill selector valve 120 is in the neutral position, the operating oil does not pass through.

On the other hand, when the check valve is connected to the one check valve (hereinafter referred to as a 'fill position') in the neutral state, the hydraulic oil can only flow into the accumulator. (Not shown).

The fill selection valve 120 is controlled by a controller C that receives information from the pressure sensor 110a.

That is, when the pressure of the accumulator 110 is low, the filling amount of the operating oil is small. Therefore, the filling selection valve 120 is controlled to the 'filling position' to fill the operating oil. On the contrary, when the pressure of the accumulator 110 is high, since the filling amount of the operating oil is large, the filling selection valve 120 is controlled to the regeneration position.

The first main regeneration valve 130 uses an electronic proportional control valve as an example and transmits the hydraulic fluid stored in the accumulator 110 to the main control valve MCV to determine whether the abandoned hydraulic energy is used for regeneration .

To this end, the hydraulic fluid discarded by the swing motor S_M is regulated in the closing direction when stored in the accumulator 110, and the hydraulic fluid is regulated in the opening direction when recovering the hydraulic fluid to the input port of the main control valve MCV.

When the first main regeneration valve 130 is adjusted in the closing direction, the supply of the hydraulic fluid to the main control valve MCV is suppressed, so that most of the hydraulic fluid is filled in the accumulator 110. Therefore, when the hydraulic energy is filled, the first main regeneration valve 130 is closed by the controller C in the closing direction.

On the contrary, when the first main regeneration valve 130 is regulated to be opened, most of the hydraulic fluid discarded from the swing motor S_M is supplied to the input port side of the main control valve MCV. The main control valve MCV is supplied to the swing motor S_M or the first actuator ACT1. In this way, when the hydraulic energy is recycled, the first main regeneration valve 130 is regulated to be opened by the controller C.

However, the amount of opening and closing of the first main regeneration valve 130 when the first main regeneration valve 130 is opened or closed may be precisely controlled in various stages as well as when the first main regeneration valve 130 is completely closed or opened according to the filling amount of the accumulator 110. Of course, the fine adjustment of the opening / closing amount also follows the control command of the controller C.

The controller C controls the main pump P, the fill selection valve 120 and the first main regeneration valve 130 and receives information on the amount of the accumulator 110 from the pressure sensor 110a . The controller C controls each of these components to be interlocked with each other so that the filling and regeneration of the hydraulic energy can be appropriately controlled as described later.

On the other hand, the first main regeneration valve 130 is installed between the fill selection valve 120 and the input port of the main control valve MCV. Therefore, the regenerated hydraulic energy is supplied from the first main regeneration valve 130 to the input port of the main control valve MCV as described above.

When the first main regeneration valve 130 is connected to the input port side of the main control valve MCV, the general main control valve MCV can be used as it is, so that it is not necessary to use the expensive IMV (refer to FIG. In addition, the hydraulic system of the excavator can be used as it is without any design changes, so it can be easily applied to existing excavators.

Further, after the regenerated hydraulic energy (i.e., hydraulic oil) is supplied to the main control valve MCV, the main control valve MCV exclusively distributes the hydraulic pressure as in the conventional case. Therefore, it is possible to utilize the regenerative energy in the first actuator ACT1 in addition to the swing motor S_M.

In other words, conventionally, the regeneration energy can be utilized only for the swing motor (see 11 in FIG. 1). In contrast, the present invention can use renewed energy for the swing motor S_M and the first actuator ACT1 do.

In addition, there is no need to interlock the main control valve (MCV) with the IMV, since a separate IMV for regenerating hydraulic energy is unnecessary. Therefore, it is not necessary to design the control logic of the main control valve (MCV) complicatedly and precisely for the interlocking of the IMV and the main control valve (MCV).

The first line (not shown) connects between one port of the swing motor S_M and the fill selector valve 120. The first check valve 141a provided in the first line 141 causes the hydraulic fluid to flow only from the swing motor S_M to the fill selector valve 120 side.

The second line 142 connects the other port of the swing motor S_M and the fill selector valve 120 and the second check valve 142a provided on the second line 142 also connects the hydraulic oil to the swing motor S_M, To the fill selection valve 120 side only.

The third line 143 is connected between the fill selector valve 120 and the first main regeneration valve 130 and the third check valve 143a provided in the third line 143 is connected to the main pump P To be supplied to the accumulator 110 or the swing motor S_M only through the main control valve MCV.

Hereinafter, the operation principle of the hybrid construction equipment according to one embodiment of the present invention will be described. The operation is largely divided into two modes, a filling mode and a regeneration mode.

First, a filling mode in which the accumulator 110 is filled with hydraulic oil will be described.

As shown in the figure, the hydraulic fluid from the A2 port of the main control valve (MCV) enters the one port of the swing motor S_M and the upper swivel is pivoted clockwise. When the upper revolving body is stopped, the hydraulic oil supplied to the revolving motor S_M is recovered to the B2 port of the main control valve MCV.

When the upper revolving body is turned in the counterclockwise direction, the hydraulic pressure of the operating oil is reversed.

At this time, if the flow rate is smaller than the reference value, the flow rate of the fluid filled in the accumulator 110 is sensed through the pressure sensor 110a. If the flow rate of the fluid is regulated to the 'fill position' Lt; / RTI >

The fill selection valve 120 is controlled by the controller C and allows the hydraulic fluid from the swing motor S_M to be filled in the accumulator 110 when the flow rate of the accumulator 110 is smaller than the reference value.

The first check valve 141a of the first line 141 and the second check valve 142a of the second line 142 prevent flow backflow when the accumulator 110 is filled with hydraulic oil. At the same time, the first main regeneration valve 130 is also opened and closed by the controller C. When filling is required, the first main regeneration valve 130 is adjusted in the closing direction.

Therefore, the working oil is prevented from being supplied to the main control valve MCV side through the third line 143, so that most of the working oil is filled in the accumulator 110. [

Particularly, when the flow rate of the accumulator 110 is determined to be lower than the minimum set value, the controller C increases the flow rate of the main pump P at the start of the excavator. This is because both the flow rate required for the upper swing body and the flow rate for filling the accumulator 110 are required.

On the other hand, when the excavator is stopped, the fill selector valve 120 is opened to prevent the accumulator 110 from being filled with operating fluid. This prevents the operating oil from being filled in the accumulator 110, thereby deteriorating the stop sensibility of the upper revolving body.

Next, a regeneration mode for regenerating the operating oil (that is, abandoned energy) filled in the accumulator 110 as described above will be described.

The controller C controls the fill selector valve 120 to the above-described 'regeneration position' and the first main regeneration valve 130 regulates the regeneration position of the accumulator 110 when the accumulator 110 has a large flow rate as a result of detection by the pressure sensor 110a Open.

The hydraulic fluid filled in the accumulator 110 sequentially passes through the fill selection valve 120, the third line 143, the third check valve 143a and the first main regeneration valve 130, Is supplied to the input port of the valve (MCV).

At this time, the controller C may cause the main pump P to start or stop. In the case where the main pump P is operated, the hydraulic pressure supplied from the main pump P and the hydraulic pressure regenerated by the main control valve MCV must be supplied in a combined manner because the working load is large. When the main pump (P) is stopped, only the regenerated hydraulic pressure is sufficient because the working load is small or the fine control is necessary.

Of course, if necessary, the main pump P may be operated by a capacity of an appropriate size to cope with a workload of a more various sizes. This makes it possible to adaptively drive every time a workload is applied.

For example, when only the swing motor S_M is operated, both the main pump P and the hydraulic pressure supplied from the accumulator 110 are used, or the hydraulic pressure supplied from either the main pump P or the accumulator 110 is used .

It is also possible to use both the hydraulic pressure supplied from the main pump P and the accumulator 110 during the operation of only the first actuator ACT1, the use of another actuator (not shown), or the fine operation, The hydraulic pressure supplied from either the accumulator (P) or the accumulator (110) can be used.

Particularly, when the various types of other actuators are used, the required pressure varies depending on the operation, so that the recycled flow rate is appropriately adjusted according to each situation even if the hydraulic pressure of the accumulator 110 is recycled.

Here, the other actuator is an optional working device, for example, an arm or a bucket actuator, which is installed and replaced in place of a bucket according to a work site. Thus, the present invention enables an adaptive response when hydraulic pressure is recycled.

Further, the fine operation means an automatic operation of an optional working device such as a small angular turning operation, arm, bucket, brake, and tongue except for a large angle swing operation or a boom operation requiring the greatest hydraulic pressure. There is a slight overlap between the other actuator and the fine actuator, but there is no significant difference in control.

Unlike the above, when the swing motor S_M and the actuator are simultaneously operated, since the work load is large, the main pump P and the hydraulic pressure supplied from the accumulator 110 are used together and the main pump P and the accumulator 110 ) Should be excluded.

Hereinafter, a hybrid construction equipment according to another embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a diagram illustrating a hydraulic system of a hybrid construction equipment according to another embodiment of the present invention.

Another embodiment of the present invention differs from the embodiment of the present invention described with reference to FIG. 2 in that not only the swing motor S_M but also the energy discharged from the boom actuator is regenerated.

3, the other embodiment of the present invention basically includes a main pump P, a main control valve MCV, a swing motor S_M, motor check valves CHV1 and CHV2, relief valves RV1 and RV2, RV2, an actuator control valve A_V, and a first actuator ACT1.

The accumulator 110 and the fill selector valve 120 are provided to store the hydraulic energy that is discarded when the swing motor S_M is started and stopped and then supplied to the first actuator ACT1 as well as the swing motor S_M, A first main regeneration valve 130, and a controller C. [

At this time, another embodiment of the present invention further includes a boom actuator 150 for operating a boom for adjusting the vertical position of the working device. The hydraulic oil drain port of the boom actuator 150 is connected to the fill selection valve 120 via the fourth line 144.

The drain port means a port on the side from which waste hydraulic oil is discharged to the accumulator 110. Since the boom actuator 150 discards the operating oil when the boom descends, the port of the boom actuator 150, Is the drain port.

The operating oil drain ports of the boom actuator 150 are connected in common to the storage tank T via the second main regeneration valve 160 as well as the fourth line 144. [ The second main regeneration valve 160 may also be an electron proportional control valve, similar to the first main regeneration valve 130 described above.

The port on the opposite side of the boom actuator 150 is connected to the storage tank through the second main regeneration valve 160. The opposite port means a port connected to the true side of the boom actuator 150 after the cylinder head.

Accordingly, when the boom descends and the discarded hydraulic fluid is generated and the flow rate filled in the accumulator 110 is small, the hydraulic oil is filled in the accumulator 110 through the fourth line 144 and the fourth check valve 144a.

The operating oil filled in the accumulator 110 is supplied to and regenerated to the main control valve MCV side via the fill selection valve 120, the third line 143 and the first main regeneration valve 130 as described above.

On the other hand, when the boom does not descend or the flow rate of the water filled in the accumulator 110 is equal to or greater than the reference value, the second main regeneration valve 160 is opened so that the operating oil is supplied to both sides of the boom actuator 150 and the storage tank T through a first boom line 145 and a second boom line 146 respectively connected to the first boom line T.

The specific embodiments of the present invention have been described above. It is to be understood, however, that the scope and spirit of the present invention is not limited to these specific embodiments, and that various modifications and changes may be made without departing from the spirit of the present invention. If you have, you will understand.

Therefore, it should be understood that the above-described embodiments are provided so that those skilled in the art can fully understand the scope of the present invention. Therefore, it should be understood that the embodiments are to be considered in all respects as illustrative and not restrictive, The invention is only defined by the scope of the claims.

P: Main pump
MCV: Main control valve
S_M: Swing motor
CHV1, CHV2: Check valve for motor
RV1, RV2: relief valve
A_V: Actuator control valve
ACT1: first actuator
C: Controller
110: accumulator
110a: Pressure sensor
120: Filling selection valve
130: first main regeneration valve
141, 142, 143, 144: hydraulic line
141a, 142a, 143a, 144a:
150: Boom actuator
160: Second main regeneration valve

Claims

A main pump (P);
A swing motor S_M which is supplied with the hydraulic fluid supplied from the main pump P through a main control valve MCV;
An accumulator 110 for storing operating fluid discarded by the swing motor S_M and supplying the operating fluid during regeneration;
A fill selection valve 120 for controlling the hydraulic oil flowing into and out of the accumulator 110;
When the operating fluid discharged from the swing motor S_M is adjusted in the closing direction when the accumulating fluid is stored in the accumulator 110 and the operating fluid discarded by the swing motor S_M is recovered to the input port of the main control valve MCV A first main regeneration valve 130 regulated in an open direction;
A controller (C) for controlling the main pump (P), the fill selector valve (120) and the first main regeneration valve (130) according to a workload;
A boom actuator 150 for operating a boom of the working device;
A fourth line 144 connecting the hydraulic oil drain port of the boom actuator 150 and the fill selector valve 120; And
A second main regeneration valve 160 for connecting the drain port of the hydraulic fluid of the boom actuator 150 to the storage tank T,
/ RTI >
When the boom does not descend or the flow rate of the filler filled in the accumulator 110 is equal to or greater than the reference value, the second main regeneration valve 160 is opened and the hydraulic fluid is recovered to the storage tank T. [ Construction equipment.

The method according to claim 1,
The first main regeneration valve (130)
Wherein the charge control valve is installed between the charge select valve and an input port of the main control valve.

The method according to claim 1,
The controller C further includes a pressure sensor 110a for sensing a filling amount of the hydraulic fluid filled in the accumulator 110. The controller C receives information on the filling amount from the pressure sensor 110a, ), A fill selection valve (120), and a first main regeneration valve (130).

The method according to claim 1,
A first line 141 connecting one port of the swing motor S_M and the fill selection valve 120, a first check valve 141a provided on the first line 141, A second check valve 142a provided in the second line 142 and a second check valve 142b connected to the fill select valve 120 A third line 143 connected between the first main regeneration valve 130 and the first main regeneration valve 130 and a third check valve 143a installed in the third line 143.

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