KR101061193B1 - Slewing Energy Regeneration Device of Excavator - Google Patents

Abstract

According to the present invention, in the turning operation process for carrying out a loading operation using an excavator, the hydraulic fluid which is relief at the time of turning deceleration after the turning acceleration of the upper turning body is stored in a high pressure accumulator, and the turning acceleration of the upper turning body is performed. In order to reduce energy consumption by using the hydraulic fluid stored in the accumulator

The swing energy regeneration device of the excavator according to the embodiment of the present invention,

Variable displacement hydraulic pump connected to the engine,

A swing motor connected to the variable displacement hydraulic pump through a first passage and a second passage, and rotated in a forward or reverse direction to pivot the upper swing structure;

A flow rate control valve installed in the first and second passages between the variable displacement hydraulic pump and the swing motor in response to an input signal from the outside and controlling the starting, stopping, and direction change of the swing motor at the time of switching;

A first passage having one end connected to the first passage and a first check valve installed;

A second passage having one end connected to the second passage and communicating with the other end of the first passage, and having a second check valve installed thereon;

A third flow passage having one end connected to the first flow passage in parallel with the first flow passage, and having a first flow control valve installed to open and close the flow path when the switch is switched according to an input signal from the outside;

A fourth flow passage having one end connected to the second flow passage in parallel with the second flow passage, and having a second flow control valve installed to open and close the flow path when the switch is switched according to an input signal from the outside;

It is installed at the intersection of the third flow path and the fourth flow path, and stores the hydraulic fluid reliefd from the first passage or the second cylinder to the hydraulic tank at the time of turning deceleration after the turning acceleration of the upper turning body, and during the turning acceleration of the upper turning body. And an accumulator for supplying the stored hydraulic oil to the first passage or the second passage.

Excavator, turning energy, regenerative device, accumulator

Description

Regeneration apparatus swing energy of excavator

The present invention relates to a revolving energy regeneration device of an excavator that allows the hydraulic oil, which is reliefd from the revolving motor to the hydraulic tank, to be stored in the accumulator and recycled when the upper frame is rotated with respect to the lower running body of the excavator.

More specifically, in the turning operation process for carrying out a loading operation using an excavator (the operation of digging sand and the like by a bucket and dumping it into a dump truck's loading box), the turning deceleration after the turning acceleration of the upper turning body. After storing the hydraulic oil relief in the high-pressure accumulator, the invention relates to a swing energy regeneration device of the excavator to reduce the energy consumption by using the hydraulic oil stored in the accumulator during the turning acceleration of the upper swing structure.

The turning device of the excavator according to the prior art shown in Figure 1,

Variable displacement hydraulic pump 1 (hereinafter referred to as "hydraulic pump") connected to the engine,

A swing motor 4 (having a motor and pump function) connected to the hydraulic pump 1 via first and second passages 2 and 3 and rotating in the forward or reverse direction to pivot the upper swing body 15; ,

It is installed in the first and second passages (2, 3) between the hydraulic pump (1) and the swing motor (4) so as to be switchable in response to a signal from the outside. And a flow control valve 5 for controlling the

A first passage 7 having one end connected to the first passage 2 and provided with a first check valve 6;

One end is branched to the first passage (2), the other end of the passage (8) which is connected to the other end of the first passage (7), the hydraulic tank is a part of the hydraulic oil when the first passage (2) is overloaded A second flow path 10 provided with a first port relief valve 9 for relieving by T2,

A third passage 12 having one end connected to the second passage 3, communicating with the other end of the first passage 7 and an intersection of the passage 8, and having a second check valve 11 installed therein; ,

One end is branch-connected to the second passage (3), communicates with the other end of the second passage (10) and the intersection of the passage (8), and when the overload occurs in the second passage (3) to the hydraulic tank (T2) And a fourth flow passage 14 in which the second port relief valve 13 to be released is installed.

At this time, the second and fourth passages 10 and 14 are parallel to the first and third passages 7 and 12 branched to the aforementioned first and second passages 2 and 3 so that the first and second passages ( It is branched to 2, 3).

In the figure, reference numeral 15 denotes an upper swinging structure which pivots the upper frame in the forward or reverse direction with respect to the lower traveling body of the excavator in accordance with the rotation of the swinging motor 4 described above.

A) The turning motor rotates in the forward direction (for example, when the hydraulic oil is supplied to the "A" port of the turning motor to rotate in the forward direction).

When the spool of the flow control valve 5 is switched to the left in the drawing according to the signal from the outside, the hydraulic pump 1 is connected to the "A" port of the swing motor 4 via the first passage 2. The "B" port of the swing motor 4 is connected to the hydraulic tank T1 through the second passage 3.

As a result, the hydraulic oil discharged from the hydraulic pump 1 is supplied to the "A" port of the swing motor 4 via the flow control valve 5 and the first passage 2 in order, so that the swing motor 4 is rotated in the forward direction. Rotate At this time, the hydraulic oil returned from the "B" port of the swing motor 4 is returned to the hydraulic tank (T1) via the second passage (3) and the flow control valve (5) in turn.

B) Explain that the swing motor rotates in the reverse direction (for example, when hydraulic oil is supplied to the "B" port of the swing motor to rotate in the reverse direction).

When the spool of the flow control valve 5 is switched to the right in the drawing in response to a signal from the outside, the hydraulic pump 1 is connected to the "B" port of the swing motor 4 through the second passage 3. The port “A” of the swing motor 4 is connected to the hydraulic tank T1 through the first passage 2.

As a result, the hydraulic oil discharged from the hydraulic pump 1 is supplied to the "B" port of the swing motor 4 via the flow control valve 5 and the second passage 3 in order, so that the swing motor 4 is reversed. Rotate At this time, the hydraulic oil returned from the "A" port of the swing motor 4 is returned to the hydraulic tank (T1) via the first passage (2) and the flow control valve (5) in turn.

Figure 2 is a graph showing the pressure of the "A" port and "B" port of the revolving motor during the loading operation using the excavator according to the prior art. At this time, the blue curve (a) means the left turning motor (LH) and the black curve (b) means the right turning motor (RH).

Section 1 and section 2 show that the upper swing body 15 is rotated and accelerated and then decelerated to rotate the upper swing body 15 to the desired swing position of the driver.

In section 1, the hydraulic oil discharged from the hydraulic pump 1 passes through the flow control valve 5 as the spool of the flow control valve 5 is turned to the left in the drawing according to the input signal from the outside. It is supplied to the "A" port along the first passage (2). On the other hand, the hydraulic oil from the "B" port is returned to the hydraulic tank T1. This rotates the turning motor 4 in the forward direction.

In section 2, a rapid deceleration of the rotating upper swing body 15 is required to switch the spool of the flow control valve 5 to the neutral position. Thus, the first passage 2 for supplying the hydraulic oil from the hydraulic pump 1 to the swing motor 4 and the second passage 3 for returning the hydraulic oil from the swing motor 4 to the hydraulic tank T1. Are respectively blocked.

At this time, due to the large weight and rotational inertia of the upper swinging body 15, a predetermined time is required for the upper swinging body 15 to stop immediately because the rotation does not stop. That is, after the flow control valve 5 is switched to the neutral position, the second passage 3 is overloaded due to the continuous rotation of the swing motor 4.

At this time, the amount of operating fluid shortened to the "A" port of the turning motor 4 which continues to rotate is sucked up from the hydraulic tank T2 through the first check 6, and the "B" of the turning motor 4 is supplemented. Hydraulic oil is discharged through the port.

As a result, the high-pressure hydraulic oil discharged from the "B" port of the swinging motor 4 is raised to the relief pressure by the second port relief valve 13 and thus acts as a force for stopping the upper swinging structure 15.

The interval 3 to the interval 4 indicates that the rotating upper swinging body 15 is rotated again in the opposite direction and then decelerated to return to the initial position.

In section 3, the hydraulic oil discharged from the hydraulic pump 1 passes through the flow control valve 5 as the spool of the flow control valve 5 is switched in the right direction on the drawing in accordance with a signal from the outside. It is supplied to the "B" port along the two paths (3). This rotates the turning motor 4 in the reverse direction. At this time, when the turning acceleration of the upper swing body 15 is increased, the hydraulic oil exceeding the set pressure generated in the second passage 3 is drained to the hydraulic tank T2 through the second port relief valve 13. At this time, since the high pressure is formed in the "B" port of the swing motor 4, the upper swing structure 15 is accelerated.

In section 4, when the upper swing body 15 is decelerated, even when the flow control valve 5 is switched to the neutral position, the swing motor 4 continues to rotate due to the rotational inertia force. Because of this, the operating flow rate that is insufficient in the "B" port of the swing motor (4) is replenished by sucking from the hydraulic tank (T2) through the second check valve (11).

At this time, the high-pressure hydraulic oil generated in the port "A" of the swing motor 4 is drained to the hydraulic tank T2 through the first port relief valve 9.

On the other hand, when the acceleration and deceleration pressure of the upper swing body 15 is low due to the micromanipulation of the joystick by the driver, the first port relief valve 9 or the second port relief valve 13 is not opened, and the flow rate control is performed. According to the spool control of the valve (5) it can control the operating flow rate supplied to the swing motor (4).

As mentioned above, in the turning device of the excavator of the prior art, too much amount of hydraulic oil is supplied to the turning motor 4 at the time of turning acceleration of the upper turning body 15. As a result, a part of the hydraulic oil passes through the first port relief valve 9 or the second port relief valve 13 and is drained into the hydraulic tank T2 to cause energy loss.

In addition, when the swinging deceleration of the upper swing body 15, the renewable hydraulic energy has a problem that is consumed through the first port relief valve 9 or the second port relief valve (13).

In an embodiment of the present invention, in the turning operation process for performing the loading operation using an excavator, the hydraulic fluid which is relief to the hydraulic tank through the relief valve at the time of turning deceleration after turning acceleration of the upper turning body to the high pressure accumulator After storage, it relates to a swing energy regenerative device of an excavator which makes it possible to reduce the energy consumption by utilizing the working oil stored in the accumulator during the swing acceleration of the upper swing structure.

The swing energy regeneration device of the excavator according to the embodiment of the present invention,

Variable displacement hydraulic pump connected to the engine,

A swing motor connected to the variable displacement hydraulic pump through a first passage and a second passage, and rotated in a forward or reverse direction to pivot the upper swing structure;

A flow rate control valve installed in the first and second passages between the variable displacement hydraulic pump and the swing motor in response to an input signal from the outside and controlling the starting, stopping, and direction change of the swing motor at the time of switching;

A first passage having one end connected to the first passage and a first check valve installed;

A second passage having one end connected to the second passage and communicating with the other end of the first passage, and having a second check valve installed thereon;

A third flow passage having one end connected to the first flow passage in parallel with the first flow passage, and having a first flow control valve installed to open and close the flow path when the switch is switched according to an input signal from the outside;

A fourth flow passage having one end connected to the second flow passage in parallel with the second flow passage, and having a second flow control valve installed to open and close the flow path when the switch is switched according to an input signal from the outside;

It is installed at the intersection of the third flow path and the fourth flow path, and stores the hydraulic fluid reliefd from the first passage or the second cylinder to the hydraulic tank at the time of turning deceleration after the turning acceleration of the upper turning body, and during the turning acceleration of the upper turning body. And an accumulator for supplying the stored hydraulic oil to the first passage or the second passage.

According to a preferred embodiment, the first flow control valve and the second flow control valve described above,

The first passage or the first port in which the flow path is formed so that the hydraulic oil from the first passage or the second passage can be always moved toward the accumulator, and the hydraulic oil stored in the accumulator when the switch is switched according to the input signal from the outside Each of the second ports supplied to the two passages is included.

Check valves are respectively provided in the flow paths of the first ports of the first flow control valve and the second flow control valve.

The turning energy regenerative apparatus of the excavator according to the embodiment of the present invention configured as described above has the following advantages.

When turning work is required to carry out the loading operation, etc., the hydraulic oil, which is released to the hydraulic tank through the relief valve at the time of turning deceleration after the turning acceleration of the upper turning body, is stored in the high pressure accumulator, and then the turning of the upper turning body By utilizing the hydraulic fluid stored in the accumulator at the time of acceleration, the amount of fuel used to drive the excavator can be reduced.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings, which is intended to explain in detail enough to enable those skilled in the art to easily practice the present invention. It is not intended that the technical spirit and scope of the invention be limited.

Turning energy regeneration device of the excavator according to the embodiment of the present invention shown in Figure 3,

Variable displacement hydraulic pump 30 is connected to the engine,

A swing motor 33 (motor and connected to the variable displacement hydraulic pump 30 through a first passage 31 and a second passage 32 and rotated in a forward or reverse direction to pivot the upper swing 41. Pump function),

It is installed in the first and second passages 31 and 32 between the variable displacement hydraulic pump 30 and the swing motor 33 so as to be switchable in response to an input signal from the outside, and when the switch is started, the swing motor 33 is started. A flow control valve 36 for controlling stop and direction change;

A first passage 38 having one end connected to the first passage 31 and provided with a first check valve 37;

A second passage 40 having one end connected to the second passage 32 so as to communicate with the other end of the first passage 38, and having a second check valve 39 installed thereon;

One end is connected to the first passage 31 in parallel with the first passage 38, and the first flow control valve 34 is installed to open and close the flow path when it is switched according to an input signal from the outside. 3 euros 42,

One end is branched to the second passage 32 in parallel with the second passage 40, and the second flow control valve 35 is installed to open and close the passage when switched according to an input signal from the outside. 4 euros 44,

Installed at the intersection of the third passage 42 and the fourth passage 44, the hydraulic tank from the first passage 31 or the second passage 32 at the time of turning deceleration after the turning acceleration of the upper swing body 41 The accumulator 45 stores the hydraulic fluid reliefd to (T) and supplies the hydraulic oil stored at the time of the acceleration of the turning of the upper swing structure 41 to the first passage 31 or the second passage 32.

The first flow control valve 34 and the second flow control valve 35 described above,

The first port 46 and the flow path are respectively formed so that the hydraulic oil from the first passage 31 or the second passage 32 can be always moved toward the accumulator 45, and can be switched according to the input signal from the outside. In this case, it includes a second port 47 for supplying the hydraulic fluid stored in the high pressure accumulator 45 to the first passage 31 or the second passage (32).

The check valve 43 is provided in each of the flow paths of the first port 46 of the first flow control valve 34 and the second flow control valve 35 described above.

Hereinafter, with reference to the accompanying drawings an example of the use of the swing energy regenerative device of the excavator according to the embodiment of the present invention.

As shown in FIG. 3, when the spool of the flow control valve 36 is switched to the left in the drawing according to an input signal from the outside, the variable displacement hydraulic pump 30 is connected to the first passage 31. The "A" port of the swing motor 33 is connected, and the "B" port of the swing motor 33 is connected to the hydraulic tank T1 through the second passage 32.

As a result, the hydraulic oil discharged from the variable displacement hydraulic pump 30 is supplied to the "A" port of the swing motor 4 via the flow control valve 36 and the first passage 31 in order, and thus the swing motor 33 ) Rotate it in the forward or reverse direction. At this time, the hydraulic oil returned from the "B" port of the swing motor 33 is returned to the hydraulic tank (T1) via the second passage 32 and the flow control valve 36 in turn.

On the other hand, when the spool of the flow control valve 36 is switched in the right direction in the drawing according to an input signal from the outside, the variable displacement hydraulic pump 30 is the swing motor 33 through the second passage 32. ) Is connected to the "B" port, the "A" port of the swing motor 33 is connected to the hydraulic tank (T1) through the first passage (31).

As a result, the hydraulic oil discharged from the variable displacement hydraulic pump 30 is supplied to the "B" port of the swing motor 33 via the flow control valve 36 and the second passage 32 in turn, so that the swing motor 33 ) Rotate it in the forward or reverse direction. At this time, the hydraulic oil returned from the "A" port of the swing motor 33 is returned to the hydraulic tank T1 via the first passage 31 and the flow control valve 36 in turn.

A) The case where the hydraulic oil drained to the hydraulic tank is stored in the accumulator during turning acceleration and turning deceleration of the upper swing structure.

3 and 2, as the spool of the flow control valve 36 is switched in the left direction according to the input signal from the outside, the variable displacement hydraulic pump 30 is the first passage ( 31 is connected to the "A" port of the swing motor 33, the "B" port of the swing motor 33 is connected to the hydraulic tank (T1) through the second passage (32).

Therefore, since the swing motor 33 is rotated by the hydraulic oil supplied from the variable displacement hydraulic pump 30 through the first passage 31, the upper swing body 41 is rotated in the forward or reverse direction.

3 and 2, when the spool of the flow control valve 36 is switched to a neutral position so as to rapidly decelerate the rotating upper swing 41, the upper swing ( Due to the large weight of 41 and the rotational inertia force, the upper swing body 41 does not immediately stop rotating. That is, after the spool of the flow control valve 36 is switched to the neutral position, the second passage 32 is overloaded due to the continuous rotation of the swing motor 33. The hydraulic fluid corresponding to the overload formed in the second passage 32 is stored in the accumulator 45 via the check valve 43 of the first port 46 of the second flow control valve 35.

At this time, the operating flow rate insufficient for the "A" port of the turning motor 33 to continue the rotation is replenished by suction from the hydraulic tank (T2) through the first check (37).

3 and 2, as the spool of the flow control valve 36 is switched in the right direction according to the input signal from the outside, the variable displacement hydraulic pump 30 is connected to the second passage ( 32 is connected to the "B" port of the swing motor 33, the "A" port of the swing motor 33 is connected to the hydraulic tank (T1) through the first passage (32).

Therefore, since the swing motor 33 is rotated by the hydraulic oil supplied from the variable displacement hydraulic pump 30 through the second passage 32, the upper swing body 41 is rotated in the forward or reverse direction.

3 and 2, when the spool of the flow control valve 36 is switched to the neutral position so as to rapidly decelerate the rotating upper swing 41, the upper swing ( Due to the large weight of 41 and the rotational inertia force, the upper swing body 41 does not immediately stop rotating. That is, after the spool of the flow control valve 36 is switched to the neutral position, an overload occurs in the first passage 31 due to the continuous rotation of the swing motor 33. The hydraulic fluid corresponding to the overload formed in the first passage 31 is stored in the accumulator 45 via the check valve 43 of the first port 46 of the first flow control valve 34.

At this time, the operating flow rate insufficient to the "B" port of the turning motor 33 to continue the rotation is replenished by suction from the hydraulic tank (T2) through the second check (39).

As described above, the hydraulic pressure of the high pressure accumulator is passed through the first flow rate control valve 34 or the second flow rate control valve 35 to the hydraulic oil relief to the hydraulic tank at the time of turning deceleration after the turning acceleration of the upper swing body 41. Storing at 45 can save hydraulic energy.

B) Explain the case of using the hydraulic oil stored in the accumulator during the turning acceleration of the upper swing structure.

As shown in FIG. 3, the hydraulic oil from the variable displacement hydraulic pump 30 is supplied to the "A" port of the swing motor 33 through the flow control valve 36 and the first passage 31 so that the upper swing structure ( In case of turning acceleration 41), the signal pressure input to switch the spool of the flow control valve 36 exceeds the set pressure (the hydraulic oil discharged from the variable displacement hydraulic pump due to excessive switching of the spool is transferred to the hydraulic tank). Refers to the set pressure exceeded enough to be released), or when the pressure in port "A" of the swing motor 33 exceeds the set pressure (the pressure of the hydraulic oil supplied to the swing motor can be released to the hydraulic tank). Refers to the set pressure exceeded enough), the switching signal is input to the first flow control valve 34 to be switched downward in the drawing (the valve spring is compressed).

For this reason, the high pressure hydraulic oil stored in the accumulator 45 is supplied to the "A" of the swing motor 33 through the second port 47 of the first flow control valve 34 and the first passage 31. do. At this time, by reducing the flow rate discharged by controlling the swash plate tilt angle of the variable displacement hydraulic pump 30, it is possible to reduce the fuel consumption for driving the variable displacement hydraulic pump 30.

On the other hand, when the pressure in the accumulator 45 is lower than or equal to the set pressure, even when the upper swing body 41 is rotated and accelerated, it is possible to change the first flow control valve 34 or the second flow control valve 35 without switching. The upper swing body 41 is rotated by the hydraulic oil discharged from the displacement hydraulic pump 30.

At this time, all of the hydraulic oil discharged from the variable displacement hydraulic pump 30 can be supplied to the swing motor 33 side, and a part of the hydraulic oil is transferred to the shaft via the first flow control valve 34 or the second flow control valve 35. It can be stored in the presser 45.

1 is a hydraulic circuit diagram showing a turning device of an excavator according to the prior art;

Figure 2 is a graph showing the pressure of the turning motor during loading operation using an excavator according to the prior art,

3 is a hydraulic circuit diagram of a swing energy regeneration device of an excavator according to an embodiment of the present invention.

* Explanation of symbols used in the main part of the drawing

30; Variable displacement hydraulic pump

31; The first passage

32; Second passage

33; Turning motor

34; 1st flow control valve

35; 2nd flow control valve

36; Flow control valve

37; First check valve

38; Euro 1

39; 2nd check valve

40; 2nd euro

41; Upper swing structure

42; 3rd euro

43; Check valve

44; Euro 4

45; Accumulator

46; 1st port

47; 2nd port

Claims (3)

A variable displacement hydraulic pump connected to the engine; A swing motor connected to the variable displacement hydraulic pump through a first passage and a second passage and rotated in a forward or reverse direction to pivot an upper swing structure; A flow rate control valve installed in the first and second passages between the variable displacement hydraulic pump and the swing motor in response to an input signal from the outside and controlling the starting, stopping, and direction change of the swing motor during switching; A first passage having one end connected to the first passage and a first check valve installed; A second passage having one end connected to the second passage and connected to the other end of the first passage, and having a second check valve installed thereon; A third flow passage having one end connected to the first passage in parallel with the first flow passage, and having a first flow control valve installed to open and close the flow passage when the first flow passage is switched according to an input signal from the outside; A fourth flow passage having one end connected to the second flow passage in parallel with the second flow passage, and having a second flow control valve installed to open and close the flow passage when it is switched according to an input signal from the outside; And It is installed at the intersection of the third flow path and the fourth flow path, and stores the hydraulic oil which is relief from the first passage or the second cylinder to the hydraulic tank at the time of turning deceleration after the acceleration of the rotation of the upper swing structure, the upper swing structure And an accumulator for supplying the stored working oil to the first passage or the second passage during the acceleration of the turning of the excavator. The method of claim 1, wherein the first flow rate control valve and the second flow rate control valve, A first port having a flow path formed therein so that the hydraulic oil from the first passage or the second passage can be always moved toward the accumulator, and the hydraulic oil stored in the accumulator when the fluid is switched according to an input signal from the outside; A turning energy regenerative apparatus for an excavator, comprising a second port for supplying one passage or a second passage, respectively. 3. The turning energy regenerative apparatus for an excavator according to claim 2, wherein a check valve is provided in each of the flow paths of the first port of the first flow control valve and the second flow control valve.

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