KR102597793B1 - Excavator - Google Patents

Abstract

The present invention relates to an excavator including a boom cylinder and a swing motor operated by hydraulic oil generated by a hydraulic pump. The excavator according to an embodiment of the present invention includes a boom operating unit that generates a pilot signal for operating the boom cylinder; , a swing operating unit that generates a pilot signal for operating the swing motor, a swing spool that controls the hydraulic oil supplied to the swing motor, and are respectively connected to both ends of the swing spool to receive a pilot signal from the swing operating unit and receive the pilot signal from the swing operating unit. A main control valve including a swing spool cap that strokes the swing spool, and selectively transmitting a pilot signal from the boom operation unit to the swing spool cap to partially cancel out the influence of the pilot signal from the swing operation unit on the swing spool. It includes a loading mode selection valve that adjusts the hydraulic oil supplied to the swing motor by selectively limiting the maximum stroke of the swing spool.

Description

Excavator{EXCAVATOR}

The present invention relates to an excavator, and more particularly to an excavator having a boom and an upper swing body.

In general, an excavator is a construction machine that performs tasks such as digging work to dig up the ground at civil engineering, architecture, and construction sites, loading work to transport earth and sand, crushing work to dismantle a building, and grading work to clear the ground. It plays a role in moving equipment. It consists of a moving body, an upper rotating body that is mounted on the traveling body and rotates 360 degrees, and a work device.

In addition, the excavator includes driving devices such as a travel motor used for traveling, a swing motor used for swinging the upper swing body, and a boom cylinder, arm cylinder, bucket cylinder, and option cylinder used in the work device. . And these driving devices are driven by hydraulic oil supplied from a hydraulic pump.

Additionally, the excavator has an operating unit including a joystick, operating lever, or pedal for controlling the various driving devices described above.

However, when an excavator performs the loading task of transporting soil, that is, loading it onto a transport vehicle, simple repetitive tasks are often continuously performed. In particular, there are many cases where the upper swing body swings at an angle of 90 degrees or less, and the boom is repeatedly raised to its maximum height and lowered for loading. When performing these tasks, the boom-up speed must be faster than the rotation speed of the upper swing body, so it is difficult for the operator to repeatedly operate the control panel to slow down the rotation speed of the upper swing body and operate the boom-up faster. Not only is it inconvenient, but it is also causing increased fatigue for workers.

An embodiment of the present invention provides an excavator that can easily control the performance of loading operations.

According to an embodiment of the present invention, an excavator including a boom cylinder and a swing motor operated by hydraulic oil generated by a hydraulic pump includes a boom operating unit that generates a pilot signal for operating the boom cylinder, and an excavator that operates the swing motor. A swing operating unit that generates a pilot signal for the swing motor, a swing spool that controls hydraulic oil supplied to the swing motor, and a swing spool connected to both ends of the swing spool to receive a pilot signal from the swing operating unit to stroke the swing spool. A main control valve including a swing spool cap, and a pilot signal from the boom operation unit is selectively transmitted to the swing spool cap to partially offset the influence of the pilot signal from the swing operation unit on the swing spool, thereby increasing the maximum control of the swing spool. It includes a loading mode selection valve that adjusts the hydraulic oil supplied to the swing motor by selectively limiting the stroke.

When the loading mode selection valve is turned on, the pilot signal of the boom operation unit is transmitted to the swing spool cap to limit the movement of the swing spool, thereby reducing the flow rate of hydraulic oil supplied to the swing motor. You can.

In addition, when the loading mode selection valve is turned on, the swing motor can rotate the upper swing body by 90 degrees or less while the boom reaches the maximum height by the boom cylinder.

The excavator is installed on a path connecting the loading mode selection valve and the swing spool cap and restricts the pilot signal generated from the boom operation unit to move only in the direction of the swing spool cap. It may further include a check valve. .

The excavator may further include a loading mode selection switch for operating the loading mode selection valve.

The swing spool cap is installed to be capable of reciprocating movement between a first area that receives the pilot signal from the swing control unit, a second area that receives the pilot signal from the boom control unit, and the first area and the second area. It may include a piston that variably adjusts the sizes of the first area and the second area.

When the piston moves and the size of the first area increases, the maximum stroke of the swing spool may increase, and when the size of the second area increases, the maximum stroke of the swing spool may decrease.

The swing spool cap includes a first stopper that limits the movement of the piston so that the first area does not shrink below a preset size, and a second stopper that limits the movement of the piston so that the second area does not shrink below a preset size. One or more of the stoppers may be further included.

The swing spool cap may further include an elastic member installed in the first area to elastically press the piston in a direction in which the first area increases.

The loading mode selection valve may include a first orifice and a second orifice having a larger diameter than the first orifice. And when the pilot signal of the boom operating unit is transmitted to the swing spool cap through the first orifice of the loading mode selection valve, it operates in the first loading mode, and the boom operating unit operates in the first loading mode through the second orifice of the loading mode selection valve. When the pilot signal of is transmitted to the swing spool cap, it can operate in the second loading mode.

In the excavator, in the first loading mode, the swing motor rotates the upper swing body to 90 degrees or less while the boom reaches the maximum height by the boom cylinder, and in the second loading mode, the boom is raised by the boom cylinder. While reaching this maximum height, the swing motor can rotate the upper pivot by more than 90 degrees and less than 180 degrees.

According to an embodiment of the present invention, an excavator can easily control the performance of loading work.

1 is a hydraulic circuit diagram for operating a swing spool used in an excavator according to a first embodiment of the present invention.
FIG. 2 is a hydraulic circuit diagram showing the operating state of the swing spool of FIG. 1.
Figure 3 is a graph showing the boom up pilot signal compared to the swing spool stroke for each operating state of the swing spool of Figure 1.
Figure 4 is a hydraulic circuit diagram for operating a swing spool used in an excavator according to a second embodiment of the present invention.
Figure 5 is a hydraulic circuit diagram showing the operating state of the swing spool of Figure 4.
Figures 6 and 7 are graphs comparing the turning speed and boom-up speed per hour and the pressure of the pilot signal per hour according to an experimental example.
Figures 8 and 9 are graphs comparing the turning speed and boom-up speed per hour and the pressure of the pilot signal per hour according to the comparative example.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in many different forms and is not limited to the embodiments described herein.

In addition, in various embodiments, components having the same configuration will be representatively described in the first embodiment using the same symbols, and in other embodiments, only configurations different from the first embodiment will be described.

Please note that the drawings are schematic and not drawn to scale. The relative dimensions and proportions of parts in the drawings are shown exaggerated or reduced in size for clarity and convenience in the drawings, and any dimensions are illustrative only and are not limiting. And for identical structures, elements, or parts that appear in two or more drawings, the same reference numerals are used to indicate similar features.

The embodiments of the present invention specifically represent ideal embodiments of the present invention. As a result, various variations of the diagram are expected. Accordingly, the embodiment is not limited to the specific shape of the illustrated area and also includes changes in shape due to manufacturing, for example.

Hereinafter, an excavator 101 according to a first embodiment of the present invention will be described with reference to FIG. 1. Although not shown, in the first embodiment of the present invention, the excavator 101 includes a boom cylinder and a swing motor that operate by hydraulic oil generated by a hydraulic pump. The boom cylinder is used to operate the boom, and the swing motor is used to swing the upper swing body.

As shown in FIG. 1, the excavator 101 according to the first embodiment of the present invention includes a boom operation unit 210, a swing operation unit 220, a main control valve 700, and a loading mode selection valve 501. Includes.

Additionally, the excavator 101 according to the first embodiment of the present invention may further include a loading mode selection switch 250.

The boom operating unit 210 generates a pilot signal for operating the boom cylinder, and the swing operating unit 220 generates a pilot signal for operating the swing motor.

In addition, the boom control unit 210 and the swing control unit 220 are provided so that the operator can operate them inside the cab of the excavator 101, and may be installed in the form of a joystick, control lever, or pedal.

Additionally, the pilot signal generated by the boom control unit 210 and the swing control unit 220 may be transmitted as the pressure of pilot signal hydraulic oil supplied by the pilot pump or as an electric signal.

The main control valve (MCV) 700 distributes the hydraulic oil generated by the hydraulic pump to various traveling devices and work devices and controls the supply of the hydraulic fluid.

Specifically, the main control valve 700 includes a plurality of control spools including a swing spool 720. Accordingly, the main control valve 700 controls the supply of hydraulic oil to the swing motor and a plurality of other hydraulic actuators. The swing spool 720 controls the hydraulic oil generated by the hydraulic pump and supplied to the swing motor.

In addition, the main control valve 700 is connected to both ends of the swing spool 720 and further includes a swing spool cap 750 that receives a pilot signal from the swing operating unit 220 and strokes the swing spool 720. Includes.

For example, an electronic proportional pressure reducing valve (EPPRV) may be installed on the swing spool cap 750, and a pilot signal transmitted as the pressure of the hydraulic oil depending on the opening and closing degree of the electronic proportional pressure reducing valve may be transmitted to the swing spool cap (750). The pressure applied to 720 changes, and the swing spool 720 moves in both directions by the pressure applied by the pilot signal.

Additionally, in addition to the swing spool 720 included in the main control valve 700, a plurality of control spools may also operate on the same principle as the swing spool 720 described above.

The loading mode selection valve 501 can be selectively turned on or off by the operator. The loading mode selection valve 501 is installed on the path connecting the boom operating unit 210 and the swing spool cap 750. That is, the loading mode selection valve 501 can selectively transmit the pilot signal of the boom operating unit 210 to the swing spool cap 750.

In this way, when the pilot signal of the boom operation unit 210 is selectively transmitted to the swing spool cap 750 by the loading mode selection valve 501, the effect of the pilot signal of the swing operation unit 220 on the swing spool 720 By partially offsetting the maximum stroke of the swing spool 720, the hydraulic oil supplied to the swing motor can be adjusted in stages.

Specifically, as shown in FIG. 2, when the loading mode selection valve 501 is turned on, the pilot signal from the boom operating unit 210 is transmitted to the swing spool cap 750, causing movement of the swing spool 720, That is, even if the swing control unit 220 generates the pilot signal to the maximum value by limiting the maximum stroke, the swing spool 720 reduces the flow rate of the hydraulic oil supplied to the swing motor compared to the state in which the loading mode selection valve is turned off. The swing speed of the upper swing body becomes slower.

At this time, the maximum stroke of the swing spool 720 may decrease as the pressure of the pilot signal generated from the boom operating unit 210 increases.

In particular, in the first embodiment of the present invention, when the loading mode selection valve 501 is turned on, the swing motor rotates the upper swing body by 90 degrees or less while the boom reaches the maximum height by the boom cylinder. It can be set to:

Specifically, in the first embodiment of the present invention, the swing spool cap 750 has a first area 751 that receives the pilot signal of the swing operating unit 220 and a second region that receives the pilot signal of the boom operating unit 210. 2 area 752, and a piston ( 755).

The piston 755 moves according to the magnitude of the pressure of the pilot signal of the boom operating unit 210 applied to the second area 752. And as the piston 755 moves, when the size of the first area 751 increases, the maximum stroke of the swing spool 720 increases, and when the size of the second area 752 increases, the swing spool 720 increases. Maximum stroke decreases.

And the swing spool cap 750 includes a first stopper 7591 that limits the movement of the piston 755 so that the first area 571 does not shrink below the preset size, and a first stopper 7591 that limits the movement of the piston 755 so that the second area 752 does not shrink below the preset size. It may further include one or more second stoppers 7592 that limit the movement of the piston 755 so that it does not decrease. If the first area 751 is reduced more than necessary, the maximum stroke of the swing spool 720 is excessively limited, and the first stopper 7591 prevents this. Additionally, if the second area 752 is reduced too much, it is difficult for the pilot signal generated from the boom operating unit 210 to be applied to the swing spool cap 750 even if the loading mode selection valve 501 is turned on. Therefore, when the loading mode selection valve 501 is turned on by securing the minimum second area 752 through the second stopper 7592, the pilot signal generated from the boom operating unit 210 is transmitted to the swing spool cap ( It allows easy application to the second area 752 of 750).

That is, the preset sizes of the first area 751 and the second area 752 may be set in various ways depending on the type of excavator 101 and the working environment.

In addition, in the first embodiment of the present invention, the swing spool cap 750 is installed in the first area 751 and includes an elastic member 758 that elastically presses the piston 755 in the direction in which the first area 751 increases. It may further include.

The elastic member 758 can adjust the relative influence of the pilot signal of the swing control unit 220 applied to the first area 751 compared to the pilot signal of the boom control unit 210 applied to the second area 752. .

In addition, the elastic member 758 pushes the piston 755 to push the piston 755 when the loading mode selection valve 501 is turned off and the pilot signal of the boom operating unit 210 applied to the second area 752 is stopped. The maximum stroke of (720) can be stably restored.

The elastic force, or spring constant, of the elastic member 758 may be set in various ways depending on the type of excavator 101 and the working environment. Additionally, when a spring is built into the swing spool 720, the spring built into the swing spool 720 can be used instead of using a separate elastic member 758 in the swing spool cap 750.

The check valve 570 is installed on the path connecting the loading mode selection valve 501 and the swing spool cap 750 so that the pilot signal generated from the boom operating unit 210 moves only in the direction of the swing spool cap 750. Restricts reverse flow to the boom control unit 210 or other directions.

The loading mode selection switch 250 is provided to operate the loading mode selection valve 501. That is, the operator can operate the loading mode selection valve 501 through the loading mode selection switch 250. However, the first embodiment of the present invention is not limited to the above, and the upper mode selection valve 501 can be switched by receiving signals in various known methods.

With this configuration, the excavator 101 according to the first embodiment of the present invention can easily control the performance of repetitive loading operations.

Specifically, as shown in FIG. 3, when the loading mode selection valve 501 is turned on, the maximum stroke of the swing spool 720 is reduced.

Therefore, while the operator operates the boom control unit 210 at the maximum value, the swing control unit 220 is simultaneously operated at the maximum value without the need to finely adjust the swing control unit 220 to an intermediate value rather than the maximum value. This makes it possible to easily perform repetitive loading operations.

In particular, according to the first embodiment of the present invention, the operation of raising and lowering the boom to the maximum height for loading can be easily and repeatedly performed while the upper swing body swings in an angle range of 90 degrees or less.

The operator can turn on the loading mode selection valve 501 only when he or she wants to perform loading work while the upper swing body swings in an angle range of 90 degrees or less. In the remaining work environments, the loading mode selection valve ( 502) can be turned off to prevent the pilot signal of the boom operating unit 210 from unnecessarily influencing the swing spool 720.

In addition, the swing speed of the upper swing body can be adjusted depending on the degree to which the maximum stroke of the swing spool 720 is limited, so the swing spool 720 can be adjusted by the loading mode selection valve 501 according to the working environment in which loading work is performed. You can also adjust the degree to which the maximum stroke is limited.

Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5.

As shown in FIG. 4, in the excavator 102 according to the second embodiment of the present invention, the loading mode selection valve 502 has a first orifice 510 and a second orifice with a larger diameter than the first orifice 510. (520) is built in. And when the loading mode selection valve 502 is turned off, the pilot signal of the boom operating unit 210 is transmitted to the swing spool cap 750 through the first orifice 510, and the loading mode selection valve 502 is When turned on, the pilot signal from the boom operating unit 210 is transmitted to the swing spool cap 750 through the second orifice 520.

When the load mode selection valve 502 is in the off state, the pilot signal of the boom control unit has little effect on the swing spool cap 750 due to the small diameter first orifice 510.

However, as shown in FIG. 5, when the loading mode selection valve 502 is turned on, the pilot signal of the boom operating unit 210 is transmitted by the second orifice 520 with a relatively large diameter to the swing spool cap ( 750), and the maximum stroke of the swing spool 720 is limited.

The specifications of the first orifice 510 and the second orifice 520 may be set in various ways depending on the type of excavator 102 and the working environment.

In addition, although not shown in FIGS. 3 and 4, in the second embodiment, the swing spool cap 750 has one or more of the first stopper 7591 or the second stopper 7592, similar to the first embodiment. It can be included.

With this configuration, the excavator 102 according to the second embodiment of the present invention can also easily control the performance of repetitive loading operations.

Additionally, the second embodiment of the present invention can be modified and implemented in various ways.

For example, when the loading mode selection valve 502 includes a first orifice 510 and a second orifice 520 with a larger diameter than the first orifice 510, the excavator 102 uses the loading mode selection valve ( When the pilot signal of the boom operating unit 210 is transmitted to the swing spool cap 750 through the first orifice 510 of 502, it operates in the first loading mode, and the second orifice 520 of the loading mode selection valve 502 ), when the pilot signal of the boom operating unit 210 is transmitted to the swing spool cap, it can operate in the second loading mode.

In the excavator 102, the swing motor rotates the upper swing body to 90 degrees or less while the boom reaches the maximum height by the boom cylinder in the first loading mode, and the boom reaches the maximum height by the boom cylinder in the second loading mode. While reaching, the swing motor can rotate the upper swing body by more than 90 degrees and less than 180 degrees.

That is, according to a modification of the second embodiment of the present invention, the operator selects the position of the loading mode selection valve 502 through the loading mode selection switch 250, thereby performing one of the 90-degree loading operation and the 180-degree loading operation. You can easily perform loading work according to your work environment by selecting .

Hereinafter, with reference to FIGS. 6 to 9, an experimental example in which the upper mode selection valve 501 is applied according to the first embodiment of the present invention and a comparative example in which the upper mode selection valve 501 is not applied will be described.

In addition, the experimental example is further divided into Experimental Example 1, in which the bucket of the excavator is empty, and Experimental Example 2, in which the bucket contains a heavy object. Figure 6 shows Experimental Example 1, and Figure 7 shows Experimental Example 2.

Comparative examples are also divided into Comparative Example 1, where the bucket is empty, and Comparative Example 2, where the bucket contains a heavy object. Figure 8 shows Comparative Example 1, and Figure 9 shows Comparative Example 2.

As shown in Figures 6 to 9, even if the boom control unit 210 and the swing control unit 220 generate the pilot signal to the maximum value, that is, the pressure of the pilot hydraulic oil to the maximum, the boom-up speed is lower than Experimental Example 1 and Experimental Example 2. While there is no significant difference compared to Comparative Example 1 and Comparative Example 2, it can be seen that the swing speed of Experimental Example 1 and Experimental Example 2 is reduced by about half compared to Comparative Example 1 and Comparative Example 2.

As such, according to the first embodiment of the present invention, that is, when the loading mode selection valve 501 is applied and turned on, the joystick, etc., which is the boom operating unit 210 and the swing operating unit 220, is operated to the maximum value. Even so, the swing speed of the upper swing body is adjusted, allowing workers to easily perform repetitive loading and unloading operations.

In addition, the swing speed of the upper swing body can be adjusted depending on the degree to which the maximum stroke of the swing spool 720 is limited, so the swing spool 720 can be adjusted by the loading mode selection valve 501 according to the working environment in which loading work is performed. It can be seen that the degree to which the maximum stroke is limited can be adjusted.

Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. will be.

Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the claims described later in the detailed description, and the meaning and scope of the claims and All changes or modified forms derived from the equivalent concept should be construed as falling within the scope of the present invention.

101, 102: Excavator
210: Boom control unit
220: Swing control unit
250: Loading mode selection switch
501, 502: loading mode selection valve
510: first orifice
520: second orifice
570: check valve
700: Main control valve
720: swing spool
750: swing spool cap
751: First area
752: Second area
755: Piston
758: Elastic member
7591: 1st stopper
7592: 2nd stopper

Claims (11)

In an excavator including a boom cylinder and a swing motor operated by hydraulic oil generated by a hydraulic pump,
a boom operating unit that generates a pilot signal for operating the boom cylinder;
a swing control unit that generates a pilot signal to operate the swing motor;
A main control including a swing spool that controls the hydraulic oil supplied to the swing motor, and a swing spool cap that is connected to both ends of the swing spool and receives a pilot signal from the swing operating unit to stroke the swing spool. valve; and
It is installed on a path connecting the boom control unit and the swing spool cap and selectively transmits the pilot signal of the boom control unit generated to operate the boom cylinder to the swing spool cap for controlling the operation of the swing motor. A loading mode selection valve that adjusts the hydraulic oil supplied to the swing motor by selectively limiting the maximum stroke of the swing spool by partially canceling the influence of the pilot signal of the swing operation unit on the swing spool.
Excavator including. According to paragraph 1,
When the loading mode selection valve is turned on, the pilot signal of the boom control unit is transmitted to the swing spool cap to limit the movement of the swing spool, thereby reducing the flow rate of hydraulic oil supplied to the swing motor by the swing spool. Featured excavator. According to paragraph 1,
When the loading mode selection valve is turned on, the swing motor rotates the upper swing body by 90 degrees or less while the boom reaches the maximum height by the boom cylinder. According to paragraph 1,
The excavator further comprises a check valve installed on a path connecting the loading mode selection valve and the swing spool cap to restrict the pilot signal generated from the boom operating unit to move only in the direction of the swing spool cap. According to paragraph 1,
An excavator further comprising a loading mode selection switch for operating the loading mode selection valve. According to paragraph 1,
The swing spool cap is,
a first area that receives a pilot signal from the swing control unit;
a second area that receives a pilot signal from the boom control unit; and
A piston is installed to be able to reciprocate between the first area and the second area to variably adjust the size of the first area and the second area.
An excavator comprising: According to clause 6,
When the piston moves and the size of the first area increases, the maximum stroke of the swing spool increases, and when the size of the second area increases, the maximum stroke of the swing spool decreases. According to clause 6,
The swing spool cap includes a first stopper that limits the movement of the piston so that the first area does not shrink below a preset size, and a second stopper that limits the movement of the piston so that the second area does not shrink below a preset size. An excavator characterized in that it further includes one or more of the stoppers. According to clause 6,
The swing spool cap further includes an elastic member installed in the first area to elastically press the piston in a direction in which the first area increases. According to paragraph 1,
The loading mode selection valve includes a first orifice and a second orifice with a larger diameter than the first orifice,
When the pilot signal of the boom operation unit is transmitted to the swing spool cap through the first orifice of the loading mode selection valve, it operates in the first loading mode,
The excavator is characterized in that it operates in the second loading mode when the pilot signal of the boom operation unit is transmitted to the swing spool cap through the second orifice of the loading mode selection valve. According to clause 10,
In the first loading mode, the swing motor rotates the upper swing body by 90 degrees or less while the boom reaches the maximum height by the boom cylinder,
In the second loading mode, the swing motor rotates the upper swing body by more than 90 degrees and less than 180 degrees while the boom reaches the maximum height by the boom cylinder.

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