KR20230165717A - Boom energy recovery hydraulic system for construction machinery - Google Patents

Abstract

The present invention relates to a boom energy recovery hydraulic system for construction equipment. By recovering the boom energy generated when the boom of a construction machine is lowered and applying it directly to the boom, it improves the boom-up speed of the boom cylinder and saves boom energy for construction. This relates to a boom energy recovery hydraulic system for construction machinery that can be used for various other operations of the machine.
According to the present invention, energy wasted when the boom is down can be recovered and utilized, and there is an advantage in that it can be easily installed or removed from existing construction machinery.

Description

Boom energy recovery hydraulic system for construction machinery {BOOM ENERGY RECOVERY HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINERY}

The present invention relates to a boom energy recovery hydraulic system for construction machinery, and more specifically, to improve the boom-up speed of the boom cylinder by recovering the boom energy generated when the boom of construction machinery is lowered and applying it directly to the boom-up. This relates to a boom energy recovery hydraulic system for construction machinery that can use boom energy for various other operations of construction machinery.

Excavators and excavators are construction machines generally used for digging or cutting the ground, and are widely used at construction sites and various industrial sites. This excavator includes a boom whose end can be moved along a curved trajectory, and various tools including a bucket can be mounted on the end of the boom.

A hydraulic cylinder is connected to the boom, and the hydraulic cylinder drives the boom while lifting and lowering. Hydraulic cylinders are raised and lowered through oil flow in the hydraulic system. An excavator includes power means such as an engine. The engine provides the fluidity of oil flow in the hydraulic system and can simultaneously provide power for the movement of the excavator.

In general, because the weight of an excavator is very large, fuel consumption due to movement is very large. Additionally, because the boom's own weight is also heavy, a lot of fuel is consumed to drive the boom.

As eco-friendly issues have recently emerged, various technological developments and research are being conducted to improve fuel efficiency in the field of construction equipment such as excavators. For example, when the boom of an excavator goes down, a technology has been proposed to recover the boom energy (potential energy) of the boom and temporarily store it to assist in moving the excavator or driving the boom.

However, this conventional technology had the problem of lowering work efficiency by imposing significant restrictions on the work operation of the boom or work speed, and also had the problem of being very difficult to install on various existing excavator cranes.

Meanwhile, when boom energy is recovered from construction machinery including an excavator or excavator, the recovered boom energy can be used to assist the driving energy of the internal combustion engine using a mechanical energy conversion unit. Additionally, the recovered boom energy is converted into electrical energy and used.

However, when converting energy to use the recovered boom energy, there are many energy conversion steps and the configuration of the conversion unit is complex, resulting in a large amount of energy loss. In addition, there was a problem that the overall manufacturing cost also increased because the manufacturing and installation costs of the conversion part for converting the boom energy were significant.

Republic of Korea Patent No. 10-2309862

Based on the technical background as described above, the present invention, in construction machinery, recovers the energy generated when the boom of the construction machinery is lowered and then uses the recovered boom energy directly in the boom cylinder to speed up the boom-up of the boom cylinder. By improving the boom-up operation, work efficiency can be improved, and boom energy can be used for various other movements of construction equipment, saving fuel and improving performance. It can be easily installed on existing construction equipment. The purpose is to provide a boom energy recovery hydraulic system for construction equipment that can be turned on or off.

A boom energy recovery hydraulic system for construction equipment according to an embodiment of the present invention includes a boom cylinder in which a rod moves up and down by the flow of oil, includes a large chamber and a small chamber formed on the upper part of the large chamber, and a boom cylinder. It includes a pressure accumulator assembly that is connected to and includes an accumulator that accumulates oil, and a boom that drives the boom up/boom down by a boom cylinder by the flow of oil, and controls the flow of oil to save energy when the boom is down. A boom energy recovery hydraulic system for construction equipment that recovers and reuses energy, comprising: a main control valve that booms up/down the boom of the boom cylinder; A valve assembly including a plurality of lines through which oil flows, and at least one valve installed in a selected line among the plurality of lines to control the flow rate of oil; An engine connected to the main pump by a shaft, providing oil flow to the boom cylinder, driving the construction machine, driving force for the bucket and arm, and swing driving force for the main body; and a control unit that controls the flow of oil based on the operation signal. It is characterized in that the oil flowing out of the large chamber is recovered and immediately reused by the boom down of the boom cylinder.

In one embodiment, the main control valve is connected to a spool that operates to direct the flow of oil toward the large chamber or small chamber of the boom cylinder, and is connected to the spool to flow oil to the large chamber by moving the spool to control the boom. A boom-up valve line that raises the boom, a boom-down valve line that is connected to the spool and causes oil to flow into the small chamber by the movement of the spool to boom-down the boom, and a spool disposed on the boom-up valve line that allows oil to flow to the large chamber. It may include a boom-up valve that controls a boom-down valve, and a boom-down valve that is disposed on the boom-down valve line and controls the spool to allow oil to flow into the small chamber.

In another embodiment, the control unit may be connected to a joystick that controls the boom up or boom down operation.

In a specific embodiment, the control unit includes a first sensor connected to the joystick, which detects a pressure change during a boom-up operation of the joystick and generates an operation signal, and is connected to the joystick, and operates by detecting a pressure change during a boom-down operation of the joystick. It is connected to a second sensor that generates a signal to receive measured values, and can control whether to open or close the boom-up valve or boom-down valve based on the manipulation signal generated by the first sensor and the second sensor.

In another specific embodiment, the control unit is connected to the third and fourth sensors that measure the hydraulic pressure of the boom cylinder and the fifth sensor that measures the pressure of the accumulator to receive measured values, and the third and fourth sensors And based on the measurement value received from the fifth sensor, the oil flow rate can be controlled by opening and closing one or more valves installed on a selected line among the plurality of lines of the valve assembly.

As one embodiment, the valve assembly includes a first line on one side connected to the large chamber of the boom cylinder, a second line connecting the first line and the accumulator, and a third line connecting the first line and the accumulator. line, a fifth line connected on one side to the small chamber of the boom cylinder, a sixth line branched from the first line and connected to the fifth line, a seventh line branched from the first line, and a fifth line and an eighth line connected on one side to the sixth line, an AC valve disposed in the second line to flow oil only toward the accumulator and to control the flow rate of the oil, and an AC valve disposed in the third line to control the flow rate of the oil. A CA valve that flows oil only toward the line and controls the oil flow rate, an AB valve that is placed in the sixth line and controls the oil flow rate, and is placed on the flow path between the accumulator and the oil tank and operates in an on-off manner. May include an actuated release valve.

In a specific embodiment, when the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure, and is disposed in the third line. By opening the CA valve, the oil accumulated in the accumulator flows into the large chamber of the boom cylinder through the third line and the first line, and the energy recovered by boom down can be used directly for boom up.

In another embodiment, the valve assembly includes a first line on one side connected to the large chamber of the boom cylinder, a second line on one side connected to the first line and the accumulator, and a third line on one side connected to the accumulator. And, a fifth line connected on one side to the small chamber of the boom cylinder, a sixth line branched from the first line and connected to the fifth line, a seventh line branched from the first line, a fifth line, and It includes an 8th line connected on one side to the 6th line, and a 9th line connecting the 3rd line and the main pump, and is disposed in the 2nd line to flow oil only toward the accumulator and to control the flow rate of the oil. AC valve, a CA valve disposed in the third line to flow oil only toward the ninth line and control the oil flow rate, an AB valve disposed in the sixth line to control the oil flow rate, and an accumulator and oil It may include a release valve disposed on the flow path between the tanks and operating in an on-off manner.

In a specific embodiment, when the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure, and is disposed in the third line. By opening the CA valve, the oil accumulated in the accumulator flows into the main pump through the 3rd and 9th lines, and the energy recovered by boom down is used to drive the engine through the main pump to drive the construction equipment and boom. It can be used directly for the driving force of cylinders, buckets, and arms, as well as the swing driving force of the main body.

As another embodiment, the valve assembly includes a first line on one side connected to the large chamber of the boom cylinder, a second line connecting the first line and the accumulator, and a valve assembly connecting the first line and the accumulator. A third line, a fifth line connected on one side to the small chamber of the boom cylinder, a sixth line branched from the first line and connected to the fifth line, a seventh line branched from the first line, and It includes an 8th line connected on one side to the 5th line and the 6th line, and a 9th line connecting the 3rd line and the main pump, and is disposed in the 2nd line to flow oil only toward the accumulator, and the oil An AC valve that controls the flow rate, and a first CA valve that is disposed on the first line adjacent to the connection portion where the first line and the third line are connected, flows oil only toward the first line, and controls the flow rate of the oil. , a second CA valve disposed in the ninth line to flow oil only through the pump through the ninth line and control the oil flow rate, an AB valve disposed in the sixth line to control the oil flow rate, and an accumulator; It may include a release valve disposed on the flow path between the oil tanks and operating in an on-off manner.

As a specific embodiment, when the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure, and is disposed in the ninth line. The second CA valve disposed in the accumulator is closed, and the first CA valve disposed in the first line adjacent to the connection portion where the first line and the third line are connected is opened, and the oil accumulated in the accumulator is supplied to the third line and the first line. By flowing it into the large chamber of the boom cylinder through the line, the energy recovered by boom down can be used directly for boom up.

In another specific embodiment, when the boom is lowered, the AC valve disposed in the second line is opened to allow the oil discharged from the large chamber to flow into the accumulator through the first line and the second line to accumulate pressure, and the first line and The first CA valve disposed in the first line adjacent to the connection portion where the third line is connected is closed, and the second CA valve disposed in the ninth line is opened to allow the oil accumulated in the accumulator to be transferred to the third line and the third line. By flowing it into the main pump through Line 9, the energy recovered by the boom down can be used to drive the engine through the main pump and be directly used for the driving force of construction machinery, the driving force of the boom cylinder, bucket, and arm, and the swing driving force of the main body.

As described above, according to the present invention, the boom energy recovery hydraulic system for construction equipment improves the boom-up speed of the boom cylinder by recovering the energy generated when the boom is lowered and then directly using the recovered boom energy in the boom cylinder. The boom-up operation can be carried out quickly to improve work efficiency, and the boom energy can be used for various other operations of construction equipment to save fuel and improve performance. Mechanical energy conversion to convert the boom energy The entire configuration can be made compact as the unit and the electric energy conversion unit can be removed, and it can be easily installed or removed from existing construction machinery.

1 is a conceptual diagram showing the overall appearance of a construction machine according to a first embodiment of the present invention.
Figure 2 is a schematic diagram showing a boom energy recovery hydraulic system for construction equipment according to a first embodiment of the present invention.
Figure 3 is a plan view showing a pressure accumulation assembly according to the first embodiment of the present invention.
Figure 4 is a perspective view showing a pressure accumulation assembly according to the first embodiment of the present invention.
Figure 5 is a plan view showing a cutaway bracket of the pressure accumulation assembly according to the first embodiment of the present invention.
Figure 6 is a schematic diagram showing the oil flow when the oil recovered from the large chamber is accumulated when the boom is lowered in the boom energy recovery hydraulic system for construction equipment according to the first embodiment of the present invention and then supplied to the large chamber to boom up. am.
Figure 7 is a schematic diagram showing a boom energy recovery hydraulic system for construction equipment according to a second embodiment of the present invention.
Figure 8 shows that in the boom energy recovery hydraulic system for construction equipment according to the second embodiment of the present invention, when the boom is down, the oil recovered from the large chamber is supplied to the main pump to drive the engine to drive the construction equipment, boom cylinder, This is a schematic diagram showing the oil flow when used as the driving force of the bucket and arm, and the swing driving force of the main body.
Figure 9 is a schematic diagram showing a boom energy recovery hydraulic system for construction equipment according to a third embodiment of the present invention.
Figure 10 is a schematic diagram showing the oil flow when the oil recovered from the large chamber is accumulated when the boom is lowered in the boom energy recovery hydraulic system for construction equipment according to the third embodiment of the present invention and then supplied to the large chamber to boom up. am.
Figure 11 shows that in the boom energy recovery hydraulic system for construction equipment according to the third embodiment of the present invention, when the boom of the boom is downed, the oil recovered from the large chamber is supplied to the main pump to drive the engine to drive the construction equipment, boom cylinder, This is a schematic diagram showing the oil flow when used as the driving force of the bucket and arm, and the swing driving force of the main body.

Since the present invention can be subjected to various modifications and can have various embodiments, specific embodiments will be exemplified and explained in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention.

The terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present invention, terms such as 'include' or 'have' are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. At this time, note that in the attached drawings, identical components are indicated by identical symbols whenever possible.

Additionally, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components are exaggerated, omitted, or schematically shown in the accompanying drawings.

(First Example)

Hereinafter, with reference to the attached drawings, the boom energy recovery hydraulic system for construction machinery according to the present invention and the construction machinery including the same will be described in detail.

1 is a conceptual diagram showing the overall appearance of a construction machine according to a first embodiment of the present invention. Figure 2 is a schematic diagram showing a boom energy recovery hydraulic system for construction equipment according to a first embodiment of the present invention. Figure 3 is a plan view showing a pressure accumulation assembly according to the first embodiment of the present invention. Figure 4 is a perspective view showing a pressure accumulation assembly according to the first embodiment of the present invention. Figure 5 is a plan view showing a cutaway bracket of the pressure accumulation assembly according to the first embodiment of the present invention. Figure 6 is a schematic diagram showing the oil flow when the oil recovered from the large chamber is accumulated when the boom is lowered in the boom energy recovery hydraulic system for construction equipment according to the first embodiment of the present invention and then supplied to the large chamber to boom up. am.

The boom energy recovery hydraulic system for construction machinery according to the first embodiment of the present invention will be described in detail. The boom energy recovery hydraulic system for construction machinery according to the first embodiment of the present invention is a structure that can be installed and dismounted on construction machinery, and can be installed on construction machinery to recover boom energy and reuse it.

To this end, construction machinery and the boom energy recovery hydraulic system for construction machinery of the present invention installed on the construction machinery will be described in detail.

When described with reference to the drawings, the boom energy recovery hydraulic system for construction equipment according to the first embodiment of the present invention includes a main control valve 160, a valve assembly 230, an engine 120, and a control unit 170. It can be configured and installed by connecting to the main body 110, boom 130, and cylinder 140 of the construction machine 100.

Specifically, a boom 130 and a boom cylinder 140 may be connected to the main body 110. The boom cylinder 140 can move up and down by the flow of oil, and the boom 130 can rotate by the up and down operation of the boom cylinder 140.

An engine 120 may be disposed inside the main body 110. The engine 120 may provide a flow of oil to the boom cylinder 140. The engine 120 may drive the construction machine 100 by providing driving force to a driving unit (not shown) disposed on the lower side of the main body 110. The engine 120 may provide a turning driving force for the main body 110, which is rotatably installed on the bucket (not shown), the arm (not shown), and the driving unit.

The operation of the boom cylinder 140 will be examined in more detail as follows. The construction machine 100 may have a cabinet 150 in the main body 110 on which a worker can ride. A joystick 151 that can control the boom-up or boom-down operation of the boom 130 may be placed in the cabinet 150.

Specifically, the boom cylinder 140 moves up and down by the flow of oil and may include a rod 141 connected to the boom 130. The boom cylinder 140 may include a large chamber 142 and a small chamber 143 formed on the large chamber 142. The large chamber 142 and the small chamber 143 may be formed in a size of 2:1.

The rod 141 is disposed between the small chamber 143 and the large chamber 142 of the boom cylinder 140, and rises when oil flows into the large chamber 142, and when oil flows into the small chamber 143, the rod 141 rises. You can descend. When the rod 141 rises, the boom 130 can boom up, and when the rod 141 falls, the boom 130 can boom down.

The pressure accumulation assembly 200 is connected to the boom cylinder 140 and discharges the accumulated pressure to the boom cylinder 140, and the oil of the boom cylinder 140 can flow in and accumulate pressure. Specifically, the pressure accumulator assembly 200 includes a bracket 210, an accumulator 220, a valve assembly 230, and a main pipe 240.

The bracket 210 is detachably fastened to the main body 110 of the construction machine 100, and the accumulator 220, valve assembly 230, and main pipe 240 are disposed on the bracket 210. The bracket 210 is a part installed on the construction machine 100, and consists of the accumulator 220, the valve assembly 230, and the main pipe 240.

The bracket 210 may be formed in a thin plate shape or a plate shape. The bracket 210 may be placed outside the construction machine 100. The bracket 210 may be provided with a fastening part (not shown) so that it can be fastened to the construction machine 100. The fastening part (not shown) may be provided, for example, with a screw hole into which a bolt can be inserted.

The bracket 210 has a main pipe 240 and a valve assembly 230 disposed on the front side facing the boom 130, a hollow portion 212 is formed on the rear side, and an axis is formed between the front side and the rear side. A press 220 may be disposed. A groove 213 may be formed on the front side of the bracket 210.

The groove portion 213 may be formed by being depressed from the front end of the bracket 210 to the rear side. The shape of the groove 213 is shaped to correspond to the shape of the outer surface of the cabinet 150 of the construction machine 100, thereby minimizing spatial interference between the cabinet 150 and the bracket 210. The main pipe 240 and the valve assembly 230 may be disposed on the front side of the bracket 210 in a portion where the groove portion 213 is not formed. That is, a groove 213 may be formed on one side of the front side of the bracket 210, and the main pipe 240 and the valve assembly 230 may be disposed on the other side.

Due to this structure of the bracket 210, the portion of the bracket 210 where the main pipe 240 and the valve assembly 230 are placed can be placed closer to the boom 130, and thus the boom cylinder 140 ) can be minimized, so the flow resistance of oil flow can be minimized.

A hollow portion 212 may be formed on the rear side of the bracket 210. The engine 120 may be disposed on the rear side of the pressure accumulation assembly 200. By using the hollow portion 212, the influence of heat generated from the engine 120 on the accumulator 220 can be reduced. Additionally, the hollow portion 212 may reduce the weight of the bracket 210. The hollow portion 212 may be formed not only on the rear side of the bracket 210, but also on the central or front side of the bracket 210.

Additionally, the accumulator 220 may be arranged to be spaced apart from the rear end (rear end) of the bracket 210. Through this, even when the accumulator assembly 200 is installed on the construction machine 100, it is convenient to open the engine room for maintenance of the engine 120, and it can be easy for workers to separate and install the accumulator 220. . In addition, it is possible to prevent heat and vibration generated from the engine 120 from being directly transmitted to the accumulator 220.

A mount 211 may be disposed between the front and rear sides of the bracket 210. The mount 211 is configured to mount the accumulator 220. The accumulator 220 can be arranged at a predetermined distance from the upper surface of the bracket 210 by the mount 211. Accordingly, the accumulator 220 can be easily separated and installed, and heat and vibration generated in the engine 120 can be prevented from being directly transmitted to the accumulator 220.

The bracket 210 may be detachably installed on the construction machine 100. The bracket 210 can be installed by modifying the exterior or interior of the existing construction machine 100. The specific size or detailed shape of the bracket 210 may be partially modified depending on the construction machine 100 to be installed. Due to this configuration of the bracket 210, the energy recovery device according to the present invention can be easily and conveniently installed on various existing construction machines 100.

Oil may be accumulated in the accumulator 220, and when necessary, oil previously accumulated in the accumulator 220 may be discharged from the accumulator 220. The main pipe 240 is connected to the boom cylinder 140. The valve assembly 230 is connected to the main pipe 240.

The main control valve 160 is connected to the boom cylinder 140 and can selectively control the flow of oil provided to the boom cylinder 140. The main control valve 160 may be placed on the construction machine 100.

Here, the main control valve 160 may be connected to the large chamber 142 through the large chamber line 144, and the main control valve 160 may be connected to the small chamber 143 through the small chamber line 145.

Additionally, a spool 161 may be disposed on the main control valve 160.

The flow of oil may be directed toward the small chamber 143 or toward the large chamber 142 by the spool 161. That is, the rod 141 of the boom cylinder 140 can rise or fall by the operation of the spool 161 disposed on the main control valve 160.

The spool 161 can be controlled by the boom up valve 163 and the boom down valve 164. An auxiliary pump 123 may be connected to the shaft 121 of the engine 120. The auxiliary pump 123 and the spool 161 are connected to the boom-up valve line 165, and the boom-up valve 163 may be disposed on the boom-up valve line 165. The auxiliary pump 123 and the spool 161 are connected to the boom down valve line 166, and the boom down valve 164 may be disposed on the boom down valve line 166. When the boom-up valve 163 opens, the spool 161 moves, allowing oil to flow into the large chamber 142, and when the boom-down valve 164 opens, the spool 161 moves, allowing oil to flow into the small chamber 143. ) can flow.

The opening and closing of the valve assembly 230 can be controlled by the pilot pipe 250, respectively. Specifically, the valve assembly 230 includes a first line (L1), a second line (L2), a third line (L3), an AC valve (AC), and a CA valve (CA).

The first line (L1) is a line connected to the large chamber 142 of the boom cylinder 140. The first line L1 may be connected to the large chamber line 144. The second line (L2) and the third line (L3) are lines connecting the first line (L1) and the accumulator 220.

An AC valve (AC) is disposed in the second line (L2). The AC valve (AC) is a valve provided to control the oil flow. It controls the flow of oil only from the second line (L2) toward the accumulator 220 and charges oil to the accumulator 220. It could be a valve.

A CA valve (CA) is disposed in the third line (L3). The CA valve (CA) is a valve provided to control the oil flow, and is a release valve that releases the oil in the accumulator 220 so that the oil flows only from the third line (L3) toward the first line (L1). It can be.

The valve assembly 230 may include a fifth line (L5) and a sixth line (L6). The fifth line (L5) is a line connected to the small chamber 143 of the boom cylinder 140. One side of the fifth line L5 may be connected to the small chamber 143 of the boom cylinder 140. The fifth line L5 may be connected to the small chamber line 145.

The sixth line (L6) is a line that branches off from the first line (L1) and is connected to the fifth line (L5). An AB valve (AB) may be disposed in the sixth line (L6) to enable control of the flow rate of oil in the sixth line (L6). The AB valve (AB) is a regeneration valve that introduces a portion of the oil flowing in the first line (L1) into the small chamber 143 of the boom cylinder 140 through the sixth line (L6) and the fifth line (L5). It can be.

The valve assembly 230 may include a seventh line (L7). The seventh line (L7) is a line that branches off from the first line (L1) and is connected to the second oil tank (T2), which will be described later. An AR valve (AR, not shown) may be further disposed in the seventh line L7 to control the flow rate of oil in the seventh line L7. When the AR valve (AR) is placed in the seventh line (L7), the AR valve (AR) is a return valve through which a portion of the oil flowing into the accumulator 220 flows into the accumulator 220 when the accumulator 220 is full of oil. It can be.

The valve assembly 230 may further include an eighth line (L8) whose one side is connected to the fifth line (L5) and the sixth line (L6). The eighth line (L8) may be connected to the third oil tank (T3), which will be described later. Through the eighth line (L8), oil that has passed through the AB valve (AB) may flow into the third oil tank (T3).

The valve assembly 230 may include a release valve (RE). The release valve (RE) is disposed on the flow path between the accumulator 220 and the first oil tank (T1), which will be described later. The release valve (RE) is disposed on the flow path between the accumulator 220 and the first oil tank (T1) and operates in an on-off manner.

The CA valve (CA), AC valve (AC), AB valve (AB), AR valve (AR, not shown), and release valve (RE) of the valve assembly 230 examined above are all operated by the control unit 170. It can be controlled.

The main pipe 240 is a pipe connected to the boom cylinder 140. One main pipe 240 is provided, and the first line (L1) and the fifth line (L5) may be formed simultaneously in the main pipe (240). Alternatively, two main pipes 240 may be provided, and a first line (L1) and a fifth line (L5) may be formed separately in each. A joint block 241 may be placed at the distal end of the main pipe 240. The large chamber 142 and the small chamber 143 of the boom cylinder 140 may be connected to the joint block 241.

The engine 120 is provided with a shaft 121, and a main pump 122 may be connected to the shaft 121. The main pump 122 and the spool 161 are connected to the main valve line 162, and oil can flow to the spool 161 and the main control valve 160 through the main valve line 162.

The oil tank (T) may be formed of at least one oil tank (T) to allow oil to flow in and be stored therein, or to allow the stored oil to flow out.

The oil tank (T) is a first oil tank (T1) connected to the release valve (RE) by piping, a second oil tank (T2) connected to the 7th line, and a third oil tank (T3) connected to the 8th line. ) may include.

Meanwhile, the boom energy recovery hydraulic system for construction equipment according to the first embodiment of the present invention may be controlled by the mobile 400, and the mobile 400 may be a terminal owned by a user or worker.

The mobile 400 may be communicatively connected to the control unit 170. Additionally, the mobile 400 may be controllably connected to the control unit 170, and the boom energy recovery hydraulic system for construction equipment may be controlled by the mobile 400.

Specifically, the operation of various devices including the main control valve 160, the valve assembly 230, and the engine 120 can be controlled through the control unit 170 based on the operation signal of the mobile 400.

The mobile 400 may be provided with an input means (not shown) for inputting control commands and an output means including a display means (not shown) for displaying various operating states.

Here, the mobile 400 may be any one of a smartphone, PDA, laptop, or tablet.

In addition, the mobile 400 can communicate with the control unit 170 through serial communication and Ethernet communication, and can communicate with the control unit 170 using Wi-Fi, Bluetooth, and Zigbee. , communication can be made possible using beacons, RFID, etc., and the communication method of the mobile 400 is not limited to this.

To this end, a program or application for controlling and operating the boom energy recovery hydraulic system for construction equipment may be installed in the mobile 400 through the control unit 170.

The control unit 170 may control the operation of the construction machine 100 based on the manipulation signal. For this purpose, the control unit 170 may be an electronic control unit (ECU).

Specifically, the control unit 170 controls the operation of various devices including the main control valve 160, the valve assembly 230, and the engine 120 based on the operation signal according to the control operation of the mobile 400. The boom energy recovery hydraulic system for construction machinery can be operated.

The control unit 170 can control whether to open or close the boom-up valve 163 or the boom-down valve 164 based on a manipulation signal according to the control operation of the mobile 400.

In addition, the control unit 170 can control the operation of the construction equipment 100 and whether the boom-up valve 163 or the boom-down valve 164 is opened or closed based on the operation signal of the joystick 151.

For this purpose, the joystick 151 may be equipped with a first sensor (S1) and a second sensor (S2). The first sensor (S1) detects the pressure change during the boom-up operation of the joystick 151 and generates a manipulation signal, and the second sensor (S2) detects the pressure change during the boom-down operation of the joystick 151 and operates it. A signal can be generated.

The operation signal generated by the first sensor (S1) and the second sensor (S2) is transmitted to the control unit 170, and the control unit 170 operates the boom-up valve 163 or the boom-down valve ( 164) can be controlled to open or close.

Here, the manipulation signal generated by the first sensor S1 and the second sensor S2 may be transmitted to the mobile 400 through the control unit 170. Through this, it is possible to control whether the boom-up valve 163 or the boom-down valve 164 is opened or closed using the mobile 400.

Meanwhile, the boom down valve 164 may also be placed in the large chamber line 144. That is, the boom down valve 164 can control not only the flow of the boom down valve line 166 but also the flow of the large chamber line 144. In this case, depending on the situation, during the boom-down operation of the joystick 151, the control unit 170 controls the boom-down valve 164 to close, allowing oil to flow from the large chamber 142 to the main control valve 160. It may also block the flow.

By the above-described structure, the oil leaking out of the large chamber 142 is recovered by the boom down of the boom cylinder 140 through the control unit 170, and is used to boom up or drive the construction machine 100, boom cylinder, and bucket. , It can be immediately reused as the driving force of the arm and the turning driving force of the main body 110.

These settings and de-settings can be accomplished by controlling the control unit 170 through the mobile device 400. Additionally, it can be controlled by the control unit 170 through a manipulation signal from the joystick 151.

Meanwhile, a third sensor (S3) and a fourth sensor (S4) may be placed on the first line (L1) and the fifth line (L5), and the third sensor (S3) and fourth sensor (S4) are always Oil pressure can be measured, and the measured oil pressure value can be transmitted to the control unit 170.

The third sensor (S3) and the fourth sensor (S4) measure the hydraulic pressure of the boom cylinder 140, the fifth sensor (S5) measures the pressure of the accumulator 220, and the control unit detects the third sensor (S3). ) and receiving the hydraulic pressure measurement value of the boom cylinder 140 through the fourth sensor (S4), receiving the hydraulic pressure measurement value of the accumulator 220 through the fifth sensor (S5), and then receiving the hydraulic pressure measurement value of the accumulator 220 through the fifth sensor (S5) And based on the measured values received from the fourth sensor (S4) and the fifth sensor (S5), the oil flow rate is controlled by opening and closing one or more valves installed on the selected line among the plurality of lines of the valve assembly 230. can do.

Hereinafter, the operation process of the boom energy recovery hydraulic system for construction machinery according to the first embodiment of the present invention will be briefly described with reference to FIG. 6.

When the boom 130 goes down, the boom down valve 164 is closed and oil flows into the small chamber 143 of the boom cylinder 140 to lower the rod 141 of the boom cylinder 140, As the rod 141 descends, the oil inside the large chamber 142 is discharged through the first line (L1).

The AC valve (AC) disposed in the second line (L2) is opened to allow oil discharged from the large chamber 122 to flow into the accumulator 220 through the first line (L1) and the second line (L2). Accumulate pressure.

Then, the CA valve (CA) disposed in the third line (L3) is opened to allow the oil accumulated in the accumulator 220 to flow into the boom cylinder 140 through the third line (L3) and the first line (L1). By flowing into the large chamber 142, the energy recovered by boom down can be directly used for boom up.

Here, when the oil accumulated in the accumulator 220 flows into the large chamber 142 of the boom cylinder 140 through the third line (L3) and the first line (L1), it is disposed in the second line (L2). By closing the AC valve (AC), the oil accumulated in the accumulator 220 can only flow into the boom cylinder 140.

At this time, since the boom down valve 164 is locked, the oil does not flow toward the main control valve 160 and can be discharged only to the first line (L1).

Through this process, the boom energy of the boom 130 can be stored in the accumulator 220, and the stored boom energy can be used to boom up the boom 130 to save fuel or improve the performance of the construction machine 100. You can do it.

In other words, the oil accumulated in the accumulator 220 immediately assists the boom-up operation of the boom 130, thereby eliminating the need for a mechanical energy conversion unit or/and an electrical energy conversion unit to convert energy, making it possible to slim the device. do.

In addition, in addition to oil flowing into the large chamber 142 through the large chamber line 144 by the main pump 122 of the engine 130, oil flows from the accumulator 220 to the third line L3 and the first The boom-up speed can be increased by increasing the amount of oil flowing into the large chamber 142, such as by flowing oil into the large chamber 142 through the line L1.

At this time, the AB valve (AB), AR valve (AR), and boom down valve 164 are closed, and only the CA valve (CA) disposed in the third line (L3) is opened to allow oil to flow into the third line (L3). And, the power required for the boom-up operation can be assisted by allowing it to flow only into the large chamber 142 through the first line (L1).

(Second Embodiment)

Figure 7 is a schematic diagram showing a boom energy recovery hydraulic system for construction equipment according to a second embodiment of the present invention. Figure 8 shows that in the boom energy recovery hydraulic system for construction equipment according to the second embodiment of the present invention, when the boom is down, the oil recovered from the large chamber is supplied to the main pump to drive the engine to drive the construction equipment, boom cylinder, This is a schematic diagram showing the oil flow when used as the driving force of the bucket and arm, and the swing driving force of the main body.

The boom energy recovery hydraulic system for construction equipment according to the second embodiment of the present invention is the first embodiment of the present invention, except that the third line connected to the accumulator is connected to the main pump of the engine through the ninth line. Since it has the same structure as the boom energy recovery hydraulic system for construction equipment according to the example, redundant description of the same configuration will be omitted.

7 and 8, the valve assembly according to the second embodiment of the present invention includes a third line (L3) on one side connected to the accumulator 220, a third line (L3), and a main pump. It may include a ninth line (L9) connecting (122).

Additionally, the CA valve (CA) is disposed in the third line (L3) to control the flow rate of oil, allowing oil to flow only from the third line (L3) toward the ninth line (L9).

Therefore, when the boom 130 goes down, the boom down valve 164 is closed, and oil flows into the small chamber 143 of the boom cylinder 140 to lower the rod 141 of the boom cylinder 140. And, as the rod 141 descends, the oil inside the large chamber 142 is discharged through the first line (L1).

The AC valve (AC) disposed in the second line (L2) is opened to allow oil discharged from the large chamber 142 to flow into the accumulator 220 through the first line (L1) and the second line (L2). It can accumulate pressure.

Then, the CA valve (CA) disposed in the third line (L3) is opened to allow the oil accumulated in the accumulator 220 to flow to the main pump 122 through the third line (L3) and the ninth line (L9). The energy recovered by the boom down is used to drive the engine 120 through the main pump 122 to drive the construction machine 100, drive the boom cylinder 140, bucket, and arm, and use the energy recovered from the boom down to drive the engine 120. It can be used directly for turning driving force.

Here, when the oil accumulated in the accumulator 220 flows into the main pump 122 through the third line (L3) and the ninth line (L9), the AC valve (AC) disposed in the second line (L2) By closing, the oil accumulated in the accumulator 220 can only flow into the main pump.

At this time, since the boom down valve 164 is locked, the oil does not flow toward the main control valve 160 and can be discharged only to the first line (L1).

Through this process, the boom energy of the boom 130 can be stored in the accumulator 220, and the stored boom energy is provided to the engine 120 to drive the construction machine 100, the boom cylinder 140, the bucket, It can be used for the driving force of the arm and the turning driving force of the main body 110.

In other words, the oil accumulated in the accumulator 220 can immediately assist the power of the engine 120, thereby saving fuel or improving the performance of the construction machine 100.

(Third Embodiment)

Figure 9 is a schematic diagram showing a boom energy recovery hydraulic system for construction equipment according to a third embodiment of the present invention. Figure 10 is a schematic diagram showing the oil flow when the oil recovered from the large chamber is accumulated when the boom is down in the boom energy recovery hydraulic system for construction equipment according to the third embodiment of the present invention and then supplied to the large chamber to boom up. am. Figure 11 shows that in the boom energy recovery hydraulic system for construction equipment according to the third embodiment of the present invention, when the boom is down, the oil recovered from the large chamber is supplied to the main pump to drive the engine to drive the construction equipment, boom cylinder, This is a schematic diagram showing the oil flow when used as the driving force of the bucket and arm, and the swing driving force of the main body.

The boom energy recovery hydraulic system for construction equipment according to the third embodiment of the present invention is, except that the third line connected to the accumulator is connected to the first line, the position of the valve is changed, and the valve is added. Since the structure is the same as that of the boom energy recovery hydraulic system for construction equipment according to the second embodiment of the invention, redundant description of the same structure will be omitted.

9 to 11, in the valve assembly according to the third embodiment of the present invention, the third line (L3) connects the first line (L1) and the accumulator 220, and the ninth line (L9) can connect the third line (L3) and the main pump (122).

Also, it is disposed on the first line (L1) adjacent to the connection portion where the first line (L1) and the third line (L3) are connected, so that the oil flows only toward the first line (L1), and the oil flow rate is adjusted. The first CA valve (CA1) that controls the second CA valve (CA2) is disposed on the ninth line (L9) and flows oil only to the main pump 122 through the ninth line (L9) and controls the flow rate of the oil. ) may include.

When the boom 130 goes down, the boom down valve 164 is closed and oil flows into the small chamber 143 of the boom cylinder 140 to lower the rod 141 of the boom cylinder 140, As the rod 141 descends, the oil inside the large chamber 142 is discharged through the first line (L1).

When the energy recovered by boom down is used directly for boom up, as shown in FIG. 10, the AC valve (AC) disposed in the second line (L2) is opened and the oil is discharged from the large chamber 142. flows into the accumulator 220 through the first line (L1) and the second line (L2) to accumulate pressure.

Then, the first CA valve (CA) disposed in the third line (L3) is opened to allow the oil accumulated in the accumulator 220 to flow into the boom cylinder 140 through the third line (L3) and the first line (L1). ) into the large chamber 142, the energy recovered by boom down can be used directly for boom up.

Here, when the oil accumulated in the accumulator 220 flows into the large chamber 142 of the boom cylinder 140 through the third line (L3) and the first line (L1), it is disposed in the second line (L2). By closing the AC valve (AC), the oil accumulated in the accumulator 220 can only flow into the boom cylinder 140.

At this time, since the boom down valve 164 is locked, the oil does not flow toward the main control valve 160 and can be discharged only to the first line (L1).

Through this process, the boom energy of the boom 130 can be stored in the accumulator 220, and the stored boom energy can be used to boom up the boom 130 to save fuel or improve the performance of the construction machine 100. You can do it.

Meanwhile, when using the energy recovered by boom down for various operations of construction equipment, as shown in FIG. 11, the AC valve (AC) disposed in the second line (L2) is opened to open the large chamber (142). ) can be accumulated by flowing the oil discharged from the oil into the accumulator 220 through the first line (L1) and the second line (L2).

Then, the second CA valve (CA2) disposed in the third line (L3) is opened to allow the oil accumulated in the accumulator 220 to be pumped through the main pump (122) through the third line (L3) and the ninth line (L9). ), the energy recovered by the boom down can be used to drive the engine 120 through the main pump 122 and be directly used for the driving force of the construction machine, the driving force of the boom cylinder, bucket, and arm, and the swing driving force of the main body. .

Here, when the oil accumulated in the accumulator 220 flows into the main pump 122 through the third line (L3) and the ninth line (L9), an AC valve (AC) disposed in the second line (L2) and The first CA valve (CA1) disposed in the first line (L1) is closed, so that the oil accumulated in the accumulator (220) flows only into the main pump (122).

At this time, since the boom down valve 164 is locked, the oil does not flow toward the main control valve 160 and can be discharged only to the first line (L1).

Through this process, the boom energy of the boom 130 can be stored in the accumulator 220, and the stored boom energy is provided to the engine to use the driving force of the construction machine, the driving force of the boom cylinder, bucket, and arm, and the swing driving force of the main body. You can use it.

The spring energy recovery hydraulic system for construction machinery according to the third embodiment of the present invention includes a first CA valve (CA1) disposed in the third line (L3) or a second CA valve (CA1) disposed in the ninth line (L9) By selectively controlling CA2), the boom energy generated when the boom 130 is lowered is used for boom-up or used as power for the engine 120, thereby improving work efficiency, saving fuel, and improving performance. You can do it.

Above, an embodiment of the present invention has been described, but those skilled in the art can add, change, delete or add components without departing from the spirit of the present invention as set forth in the patent claims. The present invention may be modified and changed in various ways, and such modifications and changes will also be included within the scope of the rights of the present invention.

100: Construction machinery
110: main body
120: engine
121: shaft
122: main pump
123: Auxiliary pump
130: boom
140: Boom cylinder
141: load
142: Large chamber
143: Small chamber
144: Large chamber line
145: Small chamber line
150: cabinet
151: Joystick
160: Main control valve
161: spool
162: Main valve line
163: Boom up valve
164: Boom down valve
165: Boom-up valve line
166: Boom down valve line
170: control unit
200: Accumulated pressure assembly
210: bracket
211: mount
212: Ministry of SMEs and Startups
213: Home Department
220: accumulator
230: Valve assembly
240: main piping
241: Joint block
250: Pilot piping
400: mobile
CA: CA valve
CA1: 1st CA valve
CA2: 2nd CA valve
AC: AC valve
AB: AB valve
RE: Release valve
L1: first line
L2: 2nd line
L3: third line
L5: 5th line
L6: 6th line
L7: 7th line
L8: 8th line
L9: 9th line
S1: first sensor
S2: second sensor
S3: Third sensor
S4: 4th sensor
S5: Fifth sensor
T: Oil tank
T1: 1st oil tank
T2: Second oil tank
T3: Third oil tank

Claims (12)

A pressure accumulation assembly including a boom cylinder in which a rod moves up and down by the flow of oil and includes a large chamber and a small chamber formed on an upper part of the large chamber, and an accumulator connected to the boom cylinder to accumulate oil, and A boom energy recovery hydraulic system for construction equipment that includes a boom driven up/down by a boom cylinder by the oil flow, and controls the flow of the oil to recover and reuse energy when the boom is down. In
A main control valve that booms up/down the boom of the boom cylinder;
a valve assembly including a plurality of lines through which the oil flows, and at least one valve installed in a selected line among the plurality of lines to control a flow rate of the oil;
An engine connected to the main pump by a shaft, providing oil flow to the boom cylinder, driving the construction machine, driving force for the bucket and arm, and swing driving force for the main body; and
A control unit that controls the flow of oil based on an operation signal;
Including,
A boom energy recovery hydraulic system for construction equipment, characterized in that the oil leaking out of the large chamber by the boom down of the boom cylinder is recovered and immediately reused.
In claim 1,
The main control valve is,
A spool that operates to direct the flow of oil to the large chamber or small chamber of the boom cylinder, a boom-up valve line connected to the spool to boom up the boom by flowing oil to the large chamber by movement of the spool, and the spool A boom-down valve line connected to the spool to flow oil into the small chamber by moving the spool to boom down the boom, and a boom-up valve disposed on the boom-up valve line to control the spool so that oil flows into the large chamber, and a boom down valve disposed on the boom down valve line and controlling the spool to allow oil to flow into the small chamber.
In claim 2,
The control unit,
A boom energy recovery hydraulic system for construction machinery, characterized in that it is connected to a joystick that controls the boom-up or boom-down operation of the boom.
In claim 3,
The control unit,
A first sensor connected to the joystick to detect a pressure change during a boom-up operation of the joystick and generate a manipulation signal, and a second sensor connected to the joystick to detect a pressure change during a boom-down operation of the joystick and generate a manipulation signal. Connected to the sensor to receive measured values,
A boom energy recovery hydraulic system for construction equipment, characterized in that it controls whether to open or close the boom-up valve or boom-down valve based on the operation signal generated by the first sensor and the second sensor.
In claim 3,
The control unit,
It is connected to a third and fourth sensor that measures the hydraulic pressure of the boom cylinder and a fifth sensor that measures the pressure of the accumulator to receive measured values,
Based on the measured values received from the third sensor, fourth sensor, and fifth sensor, the oil flow rate is controlled by opening and closing one or more valves installed on a selected line among a plurality of lines of the valve assembly. Boom energy recovery hydraulic system for construction equipment.
In claim 1,
The valve assembly is,
A first line connected on one side to the large chamber of the boom cylinder, a second line connecting the first line and an accumulator, a third line connecting the first line and the accumulator, and the boom cylinder A fifth line connected on one side to the small chamber, a sixth line branched from the first line and connected to the fifth line, a seventh line branched from the first line, and the fifth line and the sixth line It includes an 8th line where one side is connected to the 6th line,
An AC valve disposed in the second line to flow oil only toward the accumulator and control the oil flow rate; and an AC valve disposed in the third line to flow oil only toward the first line and control the oil flow rate. A construction machine comprising a CA valve, an AB valve disposed in the sixth line to control the oil flow rate, and a release valve disposed in the passage between the accumulator and the oil tank and operating in an on-off manner. For boom energy recovery hydraulic system.
In claim 6,
When the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure,
By opening the CA valve arranged in the third line, the oil accumulated in the accumulator flows into the large chamber of the boom cylinder through the third line and the first line, and the energy recovered by boom down is directly used for boom up. A boom energy recovery hydraulic system for construction machinery, characterized in that.
In claim 1,
The valve assembly is,
A first line connected on one side to the large chamber of the boom cylinder, a second line connected to the first line and an accumulator, a third line connected on one side to the accumulator, and a small chamber of the boom cylinder a fifth line connected at one end to the first line, a sixth line branched from the first line and connected to the fifth line, a seventh line branched from the first line, and the fifth and sixth lines. It includes an eighth line connected on one side to and a ninth line connecting the third line and the main pump,
An AC valve disposed in the second line to flow oil only toward the accumulator and control the oil flow rate; and an AC valve disposed in the third line to flow oil only toward the ninth line and control the oil flow rate. A construction machine comprising a CA valve, an AB valve disposed in the sixth line to control the oil flow rate, and a release valve disposed in the passage between the accumulator and the oil tank and operating in an on-off manner. For boom energy recovery hydraulic system.
In claim 8,
When the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure,
By opening the CA valve placed in the 3rd line, the oil accumulated in the accumulator flows into the main pump through the 3rd and 9th lines, and the engine is driven through the main pump with the energy recovered by boom down. A boom energy recovery hydraulic system for construction machinery that is used directly for the driving force of the machine, the driving force of the boom cylinder, bucket, and arm, and the swing driving force of the main body.
In claim 1,
The valve assembly is,
A first line connected on one side to the large chamber of the boom cylinder, a second line connecting the first line and an accumulator, a third line connecting the first line and the accumulator, and the boom cylinder A fifth line connected on one side to the small chamber, a sixth line branched from the first line and connected to the fifth line, a seventh line branched from the first line, the fifth line and the sixth line It includes an 8th line on one side connected to line 6, and a 9th line connecting the 3rd line and the main pump,
An AC valve disposed in the second line to flow oil only toward the accumulator and control the oil flow rate, and an AC valve disposed in the first line adjacent to the connection portion where the first line and the third line are connected. A first CA valve that flows oil only toward line 1 and controls the oil flow rate, and a second CA disposed in the 9th line that flows oil only through the pump through the 9th line and controls the oil flow rate. A boom for construction equipment comprising a valve, an AB valve disposed in the sixth line to control the oil flow rate, and a release valve disposed in the passage between the accumulator and the oil tank and operating in an on-off manner. Energy recovery hydraulic system.
In claim 10,
When the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure,
The second CA valve disposed in the ninth line is closed, and the first CA valve disposed in the first line adjacent to the connection portion where the first line and the third line are connected is opened to release the oil accumulated in the accumulator. A boom energy recovery hydraulic system for construction equipment that flows into the large chamber of the boom cylinder through the third line and the first line, and uses the energy recovered by boom down directly for boom up.
In claim 10,
When the boom is lowered, the AC valve disposed in the second line is opened to allow oil discharged from the large chamber to flow into the accumulator through the first and second lines to accumulate pressure,
The first CA valve disposed on the first line adjacent to the connection portion where the first line and the third line are connected is closed, and the second CA valve disposed on the ninth line is opened to allow the oil accumulated in the accumulator to flow. It flows into the main pump through the 3rd and 9th lines, and uses the energy recovered from the boom down to drive the engine through the main pump to use the driving force of the construction machine, the driving force of the boom cylinder, bucket, and arm, and the rotating driving force of the main body. A boom energy recovery hydraulic system for construction equipment that can be used immediately.

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