KR20080045314A - Excavator turning device - Google Patents

Abstract

The present invention relates to an excavator turning device, which is switched between a hydraulic pump (1), a provided turning motor (4), a neutral position and a position for turning the turning motor (4) in left and right directions, respectively. In an excavator comprising a swing valve (2) selectively communicating with a hydraulic pump (1), and a swing joystick (3) for controlling the swing valve (2), the swing joystick (3) and the swing valve (2). A first shuttle valve 21 installed at a flow path connecting the); A second shuttle valve 23 installed in a flow path connecting the swing valve 2 and the swing motor 4 to each other; It is interposed between the first and second shuttle valve 21, 23, and during operation includes a swing noise and impact protection means 30 provided to bypass the hydraulic oil filled in the swing motor (4). This results in a gentle reduction in swing pressure and a smooth speed at the preferred speed, as well as a gentle reduction in overall bypass flow rate, which also gradually increases the flow rate to the swing motor, resulting in an increase in swing torque due to excessive rotational inertia of the swing body. Preventing the dive has the effect of reducing the turning noise and impact generated when the excavator turning acceleration.

Description

Swing device for excavator

1 is a hydraulic circuit diagram showing an excavator swinging apparatus according to the prior art.

2 is a hydraulic circuit diagram showing an excavator swing device according to the present invention.

3 is an enlarged hydraulic circuit diagram of the main part of FIG. 2.

4 is a graph showing a change in pressure / speed with time of the excavator turning device.

5 is a graph showing a change in pressure / flow rate with time of the excavator turning device.

<< Explanation of symbols for main part of drawing >>

1: Hydraulic Pump 2: Swing Valve

3: turning joystick 4: turning motor

21, 23: shuttle valve

30: turning noise and impact prevention means

31, 33: valve 35: bypass check valve

37: Accumulator 39: Variable throttling valve

The present invention relates to an excavator turning device, and more particularly, to increase the flow rate supplied to the turning motor in order to prevent a sudden drop in the turning torque due to excessive rotational inertia of the turning body to reduce the turning noise and impact generated when the excavator turning acceleration It relates to an excavator turning device that can reduce the.

Referring to Figure 1, the operation relationship of the excavator swing device according to the prior art, the excavator swing device is a swing valve (2) is switched when the operator operates the swing joystick (3) and correspondingly to the swing motor (4) The flow path (A port or B port) is opened. When the swing valve 2 of the excavator swing device is switched in this way, the central bypass flow path (flow path connected to the drain port of the swing motor) of the swing valve 2 is closed, and the negative control signal is reduced, thereby reducing the pressure of the hydraulic pump 1. As the swash plate angle increases, the flow rate increases.

As described above, the rotational speed due to the rotational inertia of the swinging upper body gradually increases with constant acceleration, and in particular, the absorption flow rate of the swinging motor 4 is smaller than the supply flow rate of the flow pump 1 in this section. The relief valve of the swing motor 4 is activated.

When the turning upper body is sufficiently accelerated and the speed approaches the maximum speed, the turning torque necessary for the speed increase is sharply reduced by the rotational inertia. Therefore, the sharp decrease in the turning torque can also be confirmed through the turning pressure profile (see FIGS. 4 and 5). As a result, a sharp decrease in the swing torque increases the impact generation and thus the turning noise centered on the swing reducer.

In order to prevent such a shock and turning noise, the excavator turning device according to the prior art is provided with an anti-return valve (5). The conventional anti-return valve 5 performs a function of preventing an overshoot of speed by bypassing a small amount of flow rate at the time of turning stop and turning acceleration. However, such an anti-reversal valve 5 has a structure capable of bypassing only a small amount of flow rate in the above-described state, and thus it is impossible to prevent a perfect shock and turning noise.

Therefore, the excavator turning device according to the prior art is required to have a configuration that can bypass the large flow rate in order to prevent a sudden decrease in the turning torque or pressure during the turning acceleration.

An object of the present invention created to solve the above problems is to provide an excavator turning device that can reduce the impact and the turning noise generated during the turning acceleration of the excavator.

The object of the present invention is a hydraulic pump, a swing motor provided, a swing valve which is switched between a neutral position and a position for respectively turning the swing motor in a left / right direction and selectively communicates with the hydraulic pump, and An excavator comprising a swing joystick for controlling a swing valve, comprising: a first shuttle valve installed in a flow path connecting the swing joystick and the swing valve; A second shuttle valve installed in a flow path connecting the swing valve and the swing motor; It is interposed between the first and second shuttle valve, and during operation to be achieved by an excavator swing device comprising a swing noise and shock protection means provided to bypass the hydraulic oil filled in the swing motor. Can be.

Preferably, the turning noise and impact preventing means of the present invention comprises a first valve switched between a neutral position and a second position communicating with the first shuttle valve, an accumulator, the accumulator and the drain of the swing motor. A second valve switched between a first position communicating a port, a second position communicating the accumulator and a second position of the first valve, and a bypass check valve interposed between the accumulator and the second valve. And a variable throttling valve switched between a neutral position and a second position in communication with the second shuttle valve and the drain port of the swing motor.

Hereinafter, the configuration of the present invention with reference to the drawings in detail.

2 is a hydraulic circuit diagram showing an excavator swing device according to the present invention.

3 is an enlarged hydraulic circuit diagram of the main part of FIG. 2.

2 and 3, the excavator turning device according to the present invention is provided to be able to bypass the hydraulic oil from the turning motor (4) during the turning acceleration to prevent the sharp drop of the turning torque due to excessive rotational inertia of the turning body Noise and impact preventing means 30 and first and second shuttle valves 21 and 23 provided to operate the turning noise and impact preventing means 30 regardless of the operating direction of the turning joystick 3. Consists of.

The hydraulic circuit related to the turning device of the excavator includes a hydraulic pump (1) interlocked with the engine, a turning joystick (3), a turning valve (2), a turning motor (4), a shuttle valve (21) (23) and a turning noise and It is configured to include an impact preventing means (30).

The hydraulic pump 1 supplies or stops hydraulic oil to the swinging motor 4 by the swinging valve 2 switched to each position in response to the operation of the swinging joystick 3. Here, the swing valve 2 is switched between a neutral position and a position for turning the swing motor 4 to the left or the right, respectively.

The swing valve 2 is initially in a neutral position, and the hydraulic oil of the hydraulic pump 1 is returned again via the neutral position of the swing valve 2.

When the turning joystick 2 is operated to the left side, the turning valve 2 is switched to the second position so that the hydraulic oil of the hydraulic pump 1 flows into the A port of the turning motor 4 and turns left. ) Is operated to the right, the swing valve 2 is switched to the third position so that the hydraulic oil of the hydraulic pump 1 flows into the B port of the swing motor 4 and is turned right.

As described above, the swing joystick 2 is not operated as the swing valve 2 is neutral, and the hydraulic pump 1, the neutral position of the swing valve 2, and the drain port 4 of the swing motor 4 are operated. Mu) is in communication.

The first shuttle valve 21 according to the present invention is interposed between the flow path connecting the swing joystick 3 and the swing valve 2, the second shuttle valve 23 is the swing valve 2 and the swing motor ( It is interposed between the flow paths connecting 4).

In addition, the present invention is interposed between the first and second shuttle valves 21 and 23, and during operation, is connected to the drain port Mu of the swing motor 4 to provide a turning noise provided to bypass hydraulic oil. Impact prevention means 30 is included.

Here, the shuttle valves 21 and 23 act to be independent of the operation direction of the turning joystick 2 so that the turning noise and impact preventing means 30 is operated.

The turning noise and impact preventing means 30 of the present invention includes a first valve 31, a second valve 33, a bypass check valve 35, an accumulator 37, and a variable throttle valve 39. It is.

Firstly, the first valve 31 is switched between a neutral position and a second position in communication with the first shuttle valve 21. Here, the first valve 31 is the swing pilot pressure is increased when the swing joystick (2) is operated, thereby switching from the initial neutral state to the second position.

The second valve 33 communicates with the first position communicating the accumulator 37 and the drain port Mu of the swing motor 4 and the second position communicating the accumulator 37 and the second position of the first valve 31. Switching between 2 positions.

The bypass check valve 35 is interposed between the accumulator 37 and the second valve 33. The variable throttle valve 39 is also switched between a neutral position and a second position in communication with the drain port Mu of the second shuttle valve 33 and the swing motor 4.

In this case, the second valve 33 is operated by the turning joystick 3 so that the turning valve 2 communicates with the A or B port of the turning motor 4 so that hydraulic oil is supplied to the inlet pressure A of the turning motor 4. The pressure of the B port) rises, and this raised pressure switches to the second valve 33.

Hereinafter will be described the operational relationship of the excavator turning device according to the present invention.

When the excavator user operates the swing joystick 3 (left or right), the swing valve 2 is in communication with the A or B port of the swing motor 4 correspondingly. At this time, the turning pilot pressure switches the first shuttle valve 21 from the neutral position to the second position.

When the hydraulic oil supplied through the swing valve 2 is supplied to the swing motor 4, the inlet pressure of the swing motor 4 increases, and the increased inlet pressure of the swing motor 4 is the second shuttle valve ( 22) is switched from the neutral position to the second position. Here, when the second shuttle valve 22 is switched to the second position, the waiting pilot pressure charges the accumulator 37 through the bypass check valve 35.

The outlet pressure of the accumulator 37 acts as a pilot pressure of the variable throttle valve 39, and the variable throttle valve 39 is switched to the second position by the pilot pressure.

Therefore, when the variable throttling valve 39 is switched to the second position and communicates with the drain port Mu of the swing motor 4, the hydraulic oil flowing into the A or B port of the swing motor 4 receives the drain port Mu. Is drained through.

On the other hand, when the excavator turning device increases the turning speed so that the inlet pressure of the turning motor 4 decreases and becomes lower than the switching pressure of the second valve 33, the turning pilot pressure is cut off again and the accumulator 37 is connected to the drain port ( Communicate with Mu). Here, since the accumulator 37 is connected to the drain line communicating with the drain port Mu of the swing motor 4 through the orifice of the bypass check valve 35 and the second valve 33, the pressure of the accumulator 37 is It will fall slowly over time.

As the pressure of the accumulator 37 drops in this way, the flow rate drained through the variable throttle valve 39 also gradually decreases. At this time, the flow rate bypass through the variable throttling valve 39 is continued until the pressure of the accumulator 37 becomes equal to or less than the switching pressure.

The excavator turning device according to the present invention is configured to operate only at the time of turning acceleration, so that the flow rate is bypassed from the beginning of turning acceleration to the constant speed reaching point, and the shuttle valves 21 and 23 are turning regardless of the turning direction as described above. The noise and impact protection means 30 is provided to operate.

Therefore, the excavator turning device according to the present invention has the effect of gradually increasing the flow rate supplied to the turning motor 4 by bypassing the flow rate during the turning acceleration, so that the turning torque suddenly decreases due to excessive rotational inertia of the turning body. It is prevented at the source.

As shown in FIG. 4 and FIG. 5, the excavator swing device of the present invention has a gentle decrease in the turning pressure and smoothly reaches the maximum speed. In addition, the excavator turning device of the present invention is a flow rate supplied to the swing motor 4 because the bypass flow rate is added to the bypass flow rate through the relief valve and the anti-return valve 5 so that the overall bypass flow rate is reduced smoothly. It can be seen that gradually increased.

Although the present invention described above is limited to the above-described embodiments, the present invention is not limited thereto, and the present invention may be easily modified by those skilled in the art. It is obvious that it belongs to the technical idea of the.

According to the present invention having the above configuration, the turning pressure is gently decreased, the preferred speed is smoothly reached the maximum speed, and the overall bypass flow rate is gently reduced, so that the flow rate supplied to the swing motor is also gradually increased, thereby causing excessive rotational inertia of the swing body. It is possible to reduce the turning noise and impact generated during the excavator turning acceleration by preventing the sharp drop of the turning torque caused by.

Claims (2)

Switched between the hydraulic pump (1), the swing motor (4) provided, the neutral position and the position for turning the swing motor (4) in the left and right directions, respectively, and selectively communicates with the hydraulic pump (1) In an excavator including a swing valve (2) and a swing joystick (3) for controlling the swing valve (2), A first shuttle valve (21) installed in a flow path connecting the swing joystick (3) and the swing valve (2); A second shuttle valve 23 installed in a flow path connecting the swing valve 2 and the swing motor 4 to each other; It is interposed between the first and second shuttle valve 21, 23, and during operation includes a swing noise and impact protection means 30 provided to bypass the hydraulic oil filled in the swing motor (4). Excavator turning device, characterized in that. The method of claim 1, The turning noise and impact prevention means 30, A first valve 31 switched between a neutral position and a second position in communication with the first shuttle valve 21; With the accumulator 37, Between a first position communicating the accumulator 37 and the drain port Mu of the swing motor 4, and a second position communicating the accumulator 37 and the second position of the first valve 31. The second valve 33 switched from A bypass check valve 35 interposed between the accumulator 37 and the second valve 33, And an adjustable throttling valve (39) switched between a neutral position and a second position in communication with the second shuttle valve (23) and the drain port (Mu) of the swing motor (4). Device.

Images