KR100689289B1 - hydraulic circuit for construction heavy equipment - Google Patents

Abstract

When switching the operation device switching valve except the traveling device during construction of the construction equipment, it is possible to smoothly drive the other working equipment without interfering with the traveling speed and straightness of the heavy equipment. The left side connected to the first hydraulic pump (P1) A traveling switching valve (4), a right traveling switching valve (3) connected to the second hydraulic pump (P2), and a work device switching valve (1, 2) connected in series with the two-driving switching valves (3,4). 2, 5, 6, a switching valve (7.8) for the work device connected to the third hydraulic pump (P3) and downstream of the switching valve (7) and discharged from the third hydraulic pump (P3) during switching The switching valve (9) for supplying the operating oil to the switching valve (1, 2, 5, 6) and the two-way switching valve (3, 4) are switched and the switching valve (1, 2, 5, 6) is Hydraulic assembly for construction equipment, which is configured to operate a work device connected to the switching valves 1, 2, 5, and 6 by the hydraulic fluid discharged from the third hydraulic pump P3 during the switching. In the invention, the switching valves (1, 2, 5, 6) for the work device are formed independently of the second pilot passage (c, c1) and the second pilot passage (c, c1) in which the pilot pressure is formed when switching. And a third pilot passage f in which a pilot pressure is formed when the switching valves 7 and 8 for the work device are switched.

For this reason, when switching the work device switching valve during the operation of the heavy construction equipment, in the hydraulic circuit that can smoothly drive the working equipment without interfering with the running speed and straightness of the heavy equipment, the working device to save energy When the switching valve is switched to the work mode or the neutral mode, an automatic deceleration signal for selectively controlling the engine speed to control the oil supply amount can be applied from the switching valve to provide the operator with convenience. .

Hydraulic circuit, engine speed, selector valve, straightness, work device, construction equipment

Description

Hydraulic circuit for construction heavy equipment

1 is a hydraulic circuit diagram for heavy construction equipment according to the prior art,

2 is a hydraulic circuit diagram for construction equipment according to an embodiment of the present invention,

3 is a hydraulic circuit diagram for heavy construction equipment according to another embodiment of the present invention.

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

1,2,5,6,7,8; Switching Valve for Work Equipment

3,4; Travel switching valve

9; Joining valve

12,13; Shuttle Valve

P1; 1st hydraulic pump

P2; 2nd hydraulic pump

P3; 3rd hydraulic pump

P4; 4th hydraulic pump

A; The first passage

B; Second passage
a; Pilot port
b; First pilot aisle
c; 2nd pilot aisle
d; Pilot aisle
e; Tank passage
f; 3rd pilot aisle

The present invention relates to a hydraulic circuit for heavy construction equipment that enables to smoothly drive other working equipment without interference to the traveling speed and straightness of the heavy equipment when switching the switching valve for the working device except the traveling device during the running of the construction equipment.

More specifically, in order to drive the work device to minimize energy consumption, the engine speed is maximized when the changeover valve is switched to the working mode, and the hydraulic oil is supplied to the maximum in the neutral mode. The present invention relates to a hydraulic circuit for heavy construction equipment having a switching valve for obtaining an auto decel signal.

As schematically shown in Figure 1, the hydraulic circuit for construction equipment according to the prior art, the first to fourth hydraulic pumps (P1, P2, P3, P4) connected to the engine and driven,
A right driving switching valve (3) connected to the first hydraulic pump (P1) for controlling the hydraulic oil supplied to the right traveling motor of heavy equipment during the switching;
Left running switching valve (4) connected to the second hydraulic pump (P2) for controlling the hydraulic oil supplied to the left driving motor of the heavy equipment at the time of switching,
Switching valves 1 and 2 for the work device connected to the right driving switching valve 3 in tandem to control the hydraulic oil discharged from the first hydraulic pump P1;
Switching valves 5 and 6 for the work device connected in series with the left driving switching valve 4 to control hydraulic oil discharged from the second hydraulic pump P2;
A joining selector valve (9) connected to the third hydraulic pump (P3) for connecting the work device selector valves (7, 8), which is installed downstream thereof and is switched when the pilot signal pressure is applied through the pilot port (a). It is provided.

In the figure, reference numeral e denotes a tank passage for returning a pilot signal pressure via the auxiliary switching valve 11 to the tank T.
Accordingly, the third hydraulic pump is not applied from the fourth hydraulic pump P4 to the pilot port a so that the joining switching valve 9 is switched to the neutral position (as shown in FIG. 1). The hydraulic oil discharged from P3 is returned to the hydraulic tank T along the neutral flow path of the switching valves 7, 8 for the work device. The hydraulic fluid discharged from the first hydraulic pump P1 when the left and right traveling switching valves 3 and 4 are switched by applying the pilot signal pressure a2 or b2 (a3 or b3) from the fourth hydraulic pump P4. Is supplied to the right driving switching valve (3), the hydraulic oil discharged from the second hydraulic pump (P2) is supplied to the left driving switching valve (4) to be able to travel straight at the same speed left and right.

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At this time, in the state in which the first pilot passage (b) branched from the above-described pilot port (a) is closed, the switching valves 1, 2, 5, for work devices other than the traveling switching valves (3, 4) When 6) is switched from the fourth hydraulic pump P4 according to the application of the pilot signal pressure, a pilot signal pressure is formed in the pilot passage d while the pilot passage c is blocked, so that the above-mentioned joining switching valve 9 is provided. Switch to.

Therefore, the hydraulic oil discharged from the above-described third hydraulic pump P3 is supplied to the switching device 1, 2, 5, 6 for the work device through the first passage A and the second passage B. Accordingly, the heavy equipment can operate the work device connected to the work device change valves (1, 2, 5, 6) regardless of the traveling speed and straightness even when the work device changeover valve is changed during travel. .

However, in the case of driving the work device for energy saving in heavy equipment equipped with the hydraulic circuit configured as described above, that is, the switching valves 1 to 8 are switched to maximize the engine speed of the heavy equipment to the first hydraulic pump or the like. Automatic deceleration signal to discharge the hydraulic oil to the maximum from the third hydraulic pump (P1, P2, P3), and to minimize the hydraulic oil discharge by minimizing the engine speed when the switching valve (1-8) maintains the neutral position You will have the problem of not being able to get it.

Accordingly, an object of the present invention, when switching the switching valve for the work device during driving, using the hydraulic oil discharged from the hydraulic pump other than the hydraulic pump connected to the driving switching valve is caused interference to the running speed and straightness of heavy equipment It is to provide a hydraulic circuit for heavy equipment to improve the workability can be driven smoothly without the work device.

Another object of the present invention is to supply the maximum operating oil when switching the switching device for the work device to the working mode to save energy, and to selectively control the engine speed to minimize the operating oil supply in the neutral mode It is to provide a hydraulic circuit for heavy construction equipment that provides the operator with the convenience of operation by applying the automatic deceleration signal from the switching valve.

The object of the present invention described above, the left running switching valve (4) connected to the first hydraulic pump (P1),
A right driving switching valve 3 connected to the second hydraulic pump P2;
Switching device (1,2,5,6) for working device,
A switching valve (7.8) for the work device connected to the third hydraulic pump (P3);
A joining switching valve 9 installed downstream of the switching valve 7 to supply hydraulic oil discharged from the third hydraulic pump P3 to the switching valves 1, 2, 5, and 6 during switching;
Switching valves (1, 2, 5, 6) by the hydraulic fluid discharged from the third hydraulic pump (P3) when switching the driving valves (3, 4) for switching between two driving In the hydraulic circuit for heavy equipment is configured to operate a work device connected to),
Second pilot passages (c, c1) in which a pilot pressure is formed when the switching valves (1, 2, 5, 6) for the work device are switched;
It is formed independently of the second pilot passage (c, c1), the construction heavy equipment, characterized in that it has a third pilot passage (f) is formed when the pilot pressure is formed when switching the switching valves (7, 8) for work equipment By providing a cost hydraulic circuit.

According to a preferred embodiment, it has a pilot passage g through which a pilot pressure selected from the above-described pilot passages c1 and pilot pressures formed in the pilot passage f passes.

According to a preferred embodiment, it has a pilot passage i through which the selected pilot pressure passes among the pilot pressures formed in the pilot passage g and the pilot passage h separate from the above-described pilot passage g.

According to a preferred embodiment, the pilot passage h and the pilot passage i are formed independently of the outside.

According to a preferred embodiment, the aforementioned pilot passage g, pilot passage h and pilot passage i are formed independently of the outside.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are intended to be described in detail so that those skilled in the art to which the present invention pertains can easily carry out the present invention. It does not mean that the technical spirit and scope are limited.
2 and 3, the hydraulic circuit for heavy equipment according to the present invention, the first to fourth hydraulic pumps (P1, P2, P3, P4) connected to the engine,
A right driving switching valve 3 connected to the first hydraulic pump P1 for controlling hydraulic oil supplied to the right traveling motor;
A left driving switching valve 4 connected to the second hydraulic pump P2 for controlling hydraulic oil supplied to the left driving motor;
Switching valves for work devices (1, 2) connected in series with the right driving switch (3)
Switching valves 5 and 6 connected in series with the left driving switching valve 4;
It is provided on the downstream side of the switching valve (7) and has a joining switching valve (9) for supplying the hydraulic fluid discharged from the third hydraulic pump (P3) to the switching valve (1, 2, 5, 6), Since they apply substantially the same as those shown in FIG. 1, the following detailed description of the construction and operation thereof is omitted and the overlapping reference numerals are indicated to be the same.

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Therefore, according to a preferred embodiment of the present invention, the second pilot passage is provided with a second pilot passage (c) in which a pilot pressure is formed when the above-described switching device (1, 2, 5, 6) for the work device is switched. The pilot pressure formed in (c) passes through the shuttle valve 12, the pilot passage g, the shuttle valve 13, and the pilot passage i in order, so that the pilot signal pressure can be controlled. Can be authorized from the automatic deceleration port (ad).

In addition, a third pilot passage (f) is formed independently of the second pilot passage (c, c1) and the pilot pressure is formed when switching the switching valves (7, 8) for the work device, Since the pilot pressure formed in the passage f passes through the shuttle valve 12, the pilot passage g, the shuttle valve 13, and the pilot passage i in sequence, a pilot signal for controlling the engine speed Pressure can be applied from the automatic deceleration port (ad).

Hereinafter, the operation of the hydraulic circuit for construction equipment according to the present invention will be described in detail with reference to the accompanying drawings.

The hydraulic oil discharged from the above-mentioned third hydraulic pump P3 is returned to the hydraulic tank T via the above-mentioned switching valves 7 and 8 for the above-mentioned working apparatus in the neutral position. do. When the above-mentioned left and right traveling switching valves 3 and 4 are switched, the hydraulic oil from the first hydraulic pump P1 is supplied to the right traveling switching valve 3, and the hydraulic oil from the second hydraulic pump P2 is left. Supplied to the running switching valve (4), the heavy equipment can run straight at the same speed on the left and right.

At this time, when the switch valves 1, 2, 5, and 6 for the work device are switched while the first pilot passage b is closed, the pilot passage c is blocked and the pilot passage d is piloted. A signal pressure is formed to switch the joining switching valve 9. Since the hydraulic oil discharged from the third hydraulic pump P3 is supplied to the work device switching valves 1, 2, 5, and 6, heavy equipment is not affected by the traveling speed and straightness even when the work valve is switched. As described above, it is possible to operate the work device connected to the work valve switching valves 1, 2, 5, and 6 without using the same.

At this time, when operating the work device to reduce the energy of the heavy equipment to which the hydraulic circuit as described above, that is, the switching valves (1 to 8) when switching the engine speed of the heavy equipment to the maximum when the first hydraulic pump to Automatically discharge the hydraulic oil from the third hydraulic pump (P1, P2, P3), and the automatic deceleration signal for minimizing the hydraulic oil discharge by minimizing the engine speed when the switching valve (1-8) is switched to the neutral position It can be authorized.

That is, when the switching device valves 1, 2, 5, and 6 for the work device are switched in accordance with the application of the pilot signal pressure, a pilot pressure is formed in the second pilot passage c so that the shuttle valve 12 and the pilot passage g are provided. The pilot pressure passing through the shuttle valve 13 and the pilot passage i in turn can be applied from the automatic deceleration port ad to be used as a pilot signal pressure for controlling the engine speed.

In addition, when the above-mentioned switching device (7, 8) for the work device is switched in accordance with the pilot signal pressure applied, a pilot pressure is formed in the third pilot passage (f), so that the shuttle valve (12), the pilot passage (g), the shuttle The pilot pressure passing through the valve 13 and the pilot passage i in order can be applied from the automatic deceleration port ad to be used as a pilot signal pressure for controlling the engine speed.

In addition, when switching the above-mentioned driving switching valves 3 and 4 in accordance with the application of the pilot signal pressure, it is supplied as an external signal to the automatic deceleration port adl so that the passage h, the shuttle valve 13 and the pilot passage ( The pilot pressure passing through i) in turn can be applied from the automatic deceleration port (ad) to be used as a pilot signal pressure for controlling the engine speed.

Then, the above-described third pilot passage (f) is installed separately, i.e., independent of the auxiliary switching valve (11) to switch the left and right traveling switching valves (3, 4), the third hydraulic pump (P3) When switching the work device switching valve (7,8) connected to the confluence switching valve (9) is switched to prevent the formation of unnecessary pressure in the first passage (A) and the second passage (B), By switching of the work device switching valve (7,8) connected to the third hydraulic pump (P3), it is possible not to affect the operability of the work device to operate.

As mentioned above, according to a preferable embodiment, it has the following advantages.

When switching the operating device switching valve during construction of the construction equipment, use the working oil discharged from the hydraulic pump other than the hydraulic pump connected to the driving switching valve to smooth the working device without interfering with the traveling speed and straightness of heavy equipment. Operation can be improved.

In addition, in order to save energy, an automatic deceleration signal for selectively controlling the engine speed that controls the oil supply amount when the switching valve for the work device is switched to the working mode or the neutral mode is applied to the driver. The convenience of operation can be provided.

Claims (5)

A left driving switching valve 4 connected to the first hydraulic pump P1, A right driving switching valve 3 connected to the second hydraulic pump P2; Switching valves for work devices (1, 2, 5, 6) connected in series with the two driving switching valves (3, 4), A switching valve (7.8) for the work device connected to the third hydraulic pump (P3); A joining switching valve 9 installed downstream of the switching valve 7 to supply hydraulic oil discharged from the third hydraulic pump P3 to the switching valves 1, 2, 5, and 6 during switching; A first pilot passage b for blocking a signal pressure passage when the driving switching valves 3 and 4 are switched; When switching the driving switching valves (3, 4) and switching the switching valves (1, 2, 5, 6) by the operating oil discharged from the third hydraulic pump (P3) switching valves (1, 2, 5, In a hydraulic circuit for heavy equipment constructed to operate a work tool connected to 6): Second pilot passages (c, c1) in which pilot pressure is formed when the switching valves (1, 2, 5, 6) for the work device are switched; And Independently formed with respect to the second pilot passage (c, c1), characterized in that it comprises a third pilot passage (f) for the pilot pressure is formed when switching the switching valves (7, 8) for the working device Hydraulic circuit for heavy construction equipment. The hydraulic circuit of claim 1, further comprising a pilot passage (g) through which a pilot pressure selected from the pilot pressures formed in the second pilot passage (c1) and the third pilot passage (f) passes. . 3. The hydraulic circuit according to claim 2, further comprising a pilot passage (i) through which a pilot pressure selected from the pilot pressures formed in the pilot passage (g) and the pilot passage (h) passes. 4. The hydraulic circuit for heavy construction equipment according to claim 3, wherein the pilot passage (h) and the pilot passage (i) are formed independently from the outside. 4. The hydraulic circuit for heavy construction equipment according to claim 3, wherein the pilot passage (g), the pilot passage (h) and the pilot passage (i) are formed independently from the outside.

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