KR100406275B1 - hydraulic circuit for heavy equipment option device - Google Patents

Abstract

The present invention can be detachably equipped with an optional device such as a breaker or a shear at the tip of the working device of the excavator according to the working conditions to prevent the leakage of oil due to the high operating conditions and long-term use during operation It is installed to communicate with the flow path between the main switching valve and the optional device.If the operating pressure of the optional device is high, it prevents leakage of the working oil during operation.If the operating pressure of the optional device is low, the hydraulic oil is returned from the optional device. The first and second poppets which are operated to be connected to one of the first and second poppets and connected to any one of the first and second poppets, and are operated when the operating signal pressure is supplied from the outside to return the working oil discharged from the optional device to the tank. Offer off the split.

This prevents leakage due to temperature rise from the select valve that is selectively mounted at the tip of the working device of the excavator and controls the flow direction of the hydraulic oil supplied to the optional device operated at high pressure, thereby securing a safe working environment. It increases the reliability and simplifies the flow path formed inside the select valve, thereby reducing the size of the corresponding parts and reducing the pressure loss, thereby greatly improving the durability of the optional device.

Description

Hydraulic circuit for heavy equipment option device

The present invention detachably mounts an optional device such as a breaker or a shear at the tip of the working device of the excavator according to the working conditions, so that oil leakage occurs due to the high operating pressure and long time use. It relates to a hydraulic circuit for heavy equipment option to prevent it from becoming.

In particular, when supplying high-pressure hydraulic fluid to an option device with a relatively high working pressure, it is minimized to be leaked by a poppet installed to be switched to a select valve that controls the flow direction of the hydraulic fluid. It relates to a hydraulic circuit for the heavy equipment option that can be secured.

The hydraulic circuit for the heavy equipment option device according to the prior art is shown in FIG.

When working with a breaker with a relatively low working pressure at the tip of the work device of the excavator, the pilot signal pressure Pb by the operator is applied to the left end of the main switching valve 1 and the top of the select valve 2. The hydraulic fluid discharged from the hydraulic pump P1 is supplied to an optional device (referred to as a breaker) 3 through the main switching valve 1 switched to the right direction, and is driven. The hydraulic oil discharged from (3) is returned to the tank (T) via the selector valve (2) switched downward.

On the other hand, in the case of using the share with a relatively higher operating pressure than the breaker as the option device 3 described above, the pilot signal pressure Ps by the operator is applied to the right end of the main switching valve 1, the left side in the drawing. And the hydraulic fluid discharged from the hydraulic pump P1 are supplied to the option device 3 via the select valve 2 which maintains neutral after passing through the switched main switching valve 1. At this time, the hydraulic oil discharged from the option device (3) is returned to the tank (T) via the main switching valve (1) switched to the left direction.

However, as shown in FIG. 2, the above-described select valve 2 is built in so that the spool 2a can be shifted so as to determine the flow direction of the hydraulic oil when the driving signal is applied from the outside. For this reason, when using a share having a relatively higher operating pressure than the breaker as the option device 3, when the oil leaks through a gap of the spool 2a internally inside the block, a heavy oil load is picked up and transported. Due to the risk of dropping the object picked up during transport, this has a problem that the amount of oil leakage is more and more when the temperature of the working oil rises due to long time operation.

In addition, when using a breaker with a relatively low operating pressure as an option device, the pressure loss due to leakage is large, which has a problem of reducing the durability due to the load generated in the breaker having a low back pressure limit. As a result, when the size of the spool 2a is increased to reduce the pressure loss, the overall size of the select valve 2 is increased, which causes problems in cost and mounting space.

Accordingly, an object of the present invention is to be mounted on the tip of the working device of the excavator selectively prevents leakage due to the temperature rise from the select valve for controlling the flow direction of the hydraulic oil supplied to the option device operated at high pressure to ensure a safe working environment It is to provide a hydraulic circuit for the heavy equipment option device to secure the equipment reliability by securing.

Another object of the present invention is to provide a hydraulic circuit for a heavy equipment option device that can greatly improve the durability of the optional device by reducing the size of the corresponding parts by simplifying the flow path formed inside the select valve. .

1 is a schematic diagram of a hydraulic circuit for a heavy equipment option device according to the prior art,

2 is an internal cross-sectional view of the select valve shown in FIG.

3 is a schematic diagram of a hydraulic circuit for a heavy equipment option device according to the present invention;

4 is an internal cross-sectional view of the select valve body shown in FIG. 3;

FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 4.

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

One; Main switching valve

3; Option device

4; Poppet

5; 2nd poppet

6; On / off split

7; Solenoid valve

8; Select valve body

9; cover

10; filter

An object of the present invention described above, the main unit for controlling the flow direction of the hydraulic oil, the optional device connected to the hydraulic pump to drive the hydraulic oil supply, and installed in the flow path between the hydraulic pump and the optional device supplied to the option device In the hydraulic circuit for heavy equipment option device having a switching valve, it is installed to open and close the flow path between the main switching valve (1) and the option device (3), the operating pressure of the option device (3) is low pressure In this case, the first poppet 4 which blocks the flow path and the first poppet 4 and the option device 3 are installed to open and close the flow path, and the operating pressure of the option device 3 is low. In the case where the downstream side is drained and the second poppet (5) which is installed to be seated when the operating pressure of the option device 3 is a high pressure, the second poppet (5) is installed in the flow path between the downstream side and the tank, The second bag is operated by supplying the signal pressure from the outside. Achieved by providing a hydraulic circuit for the heavy equipment option, characterized in that it comprises an on / off spool (6) for draining the downstream side of the pet (5) to return the working oil discharged from the option device (3) to the tank. do.

According to a preferred embodiment, when the operating pressure of the option device is low, the option device 3 is removed from the foreign matter contained in the hydraulic oil returned from the option device 3 through the second poppet 5. It is provided with a filter 10 installed in the return flow path to protect.

It is also provided with a solenoid valve (7) for switching when the electrical signal is applied by a driver or a remote control valve by the driver to supply the operating pressure to the on / off spool (6).

In addition, when the operating pressure of the option device 3 is a high pressure, the first poppet (4) forming a boundary between the high pressure working oil and the low pressure drain side to prevent leakage through the first poppet (4) It is provided with a sealing (11) attached to the sliding portion of.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 to 5, between the hydraulic pump P1 and the optional device 3 connected to the hydraulic pump P1 and driven by hydraulic oil supply, between the hydraulic pump P1 and the optional device 3. The main switching valve (1) and the main switching valve (1) and the flow path between the main switching valve (1) and the optional device (3) are installed in the flow path of the main control valve to control the flow direction of the hydraulic oil supplied to the option device (3). When the operating pressure of the option device 3 is low, the first poppet 4 which blocks the flow path and the flow path between the first poppet 4 and the option device 3 can be opened and closed. The downstream side is drained when the working pressure of the device 3 is low and the second poppet 5 is installed to be seated when the working pressure of the option device 3 is high.

At this time, preferably, the option device 3 can be protected from foreign matter such as dust contained in the hydraulic oil returned through the second poppet 5 from the above-described option device 3 having a low working pressure. The filter 10 is installed and is switched when an electric signal is applied by a driver or a remote control valve (not shown) by the driver to supply the pilot operating pressure to the on / off split 6 and the pilot pump P2. A solenoid valve 7 may be installed in the flow path between the branched first poppet 4 and the on / off split 6.

Further, preferably, when the operating pressure of the above-described option device 3 is a high pressure, the main switching valve 1 passes through the first and second poppets 4 and 5 to prevent leakage of oil. A sealing spring 11 is mounted on the sliding portion of the first poppet 4 forming a boundary between the high pressure oil and the low pressure drain, and maintains a neutral state to block the second poppet 5 from flowing. 6a is provided to the on / off split 6.

Reference numeral 9 denotes a cover which is attached to the outer surface of the select valve body 8 to form a pilot signal pressure Pi inlet and a drain dr port.

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

The following describes a case where a breaker which can be driven at a low pressure with a relatively low working pressure is mounted on the tip of an excavator working device.

As shown, the pilot oil pressure (Pb) by the driver is applied to the left end of the above-mentioned main switching valve (1) to switch in the right direction in the drawing, the hydraulic fluid discharged from the hydraulic pump (P1) is It is supplied to the option device 3 (referred to a breaker) via the main switching valve 1 switched in the right direction.

On the other hand, the electrical signal due to the operation of the remote control valve (RCV) or the pedal (not shown) by the driver is applied to the above-described solenoid valve (7) to switch to the left side in the drawing, the pilot pump (P2) The pilot signal pressure Pi discharged from the () flows into the above-mentioned select valve body 8 via the switched solenoid valve 7.

That is, part of the pilot signal pressure Pi presses the upper end of the first poppet 4 to block the "B" port toward the main switching valve 1 side, and at the same time, the pilot signal pressure Pi is partially on / off. The upper end of the second poppet 5 is drained by being applied to the right end of the spool 6 to the left in the drawing. Thus, the hydraulic oil discharged from the above-described option device 3 is " A " The option device 3 is operated as the second poppet 5 is pushed upward through the port and returned to the tank T.

At this time, since the first poppet 4 described above is pressurized and seated by the pilot signal pressure Pi, the total flow rate returned is not flowed into the "B" port but the tank T via the "T" port. Is returned. The filter 10 may be mounted on the return flow path between the above-mentioned "T" port and the tank T so as to protect against foreign matter such as dust due to the working characteristics of the option device 3.

On the other hand, when the above-mentioned first poppet (4) is pressed by the pilot signal pressure Pi to block the flow path to the "B" port in detail, it is discharged from the option device (3) to "A" The low-pressure return oil returning from the port to the "T" port lifts the second poppet 5 with a force of Pa x (øy-øx), which flows into the signal pressure introducing portion formed in the cover 9 described above. The pilot signal pressure Pi operates in the direction of seating the first poppet 4 as a force of (Ppi x øy).

At this time, the low pressure oil returned is sufficiently smaller in pressure and cross-sectional area than the pilot signal pressure Ppi, so that the low pressure oil can be sheeted to block the "B" port.

On the other hand, the case where a share or crumb cell capable of driving at a high pressure with a higher operating pressure than the breaker is used as an option is described.

As the pilot signal pressure Ps by the driver is applied to the right end of the above-mentioned main switching valve 1 and switches it to the left side in the drawing, the hydraulic fluid discharged from the hydraulic pump P1 is switched to the main switching. After passing through the valve 1, it is supplied to the option device 3 (referred to as share) via the first and second poppets 4 and 5. The first end of the first poppet 4 described above is Since it is drained to the tank T through the pilot passage and the solenoid valve 7 in a neutral state, the first poppet 4 is pushed up by the high pressure hydraulic oil supplied to the port "B" to move to the second poppet 5 side. do.

On the other hand, as the hydraulic oil discharged from the above-described option device 3 is returned to the tank T via the switched main switching valve 1, the share can be operated. At this time, since the optional device (3) is operated as a high pressure due to the characteristics of the equipment it is possible to prevent the leakage of oil due to the temperature rise during working conditions and long time operation.

That is, when the high pressure operating oil passing through the main switching valve 1 passes through the first poppet 4, the sealing 11 is mounted on the sliding part of the first poppet 4 which forms a boundary with the drain side of the low pressure state. Oil leakage through the first poppet (4) is prevented, and neutral pressure is maintained by the valve spring (6a) when the high pressure hydraulic fluid passing through the first poppet (4) passes through the second poppet (5). Since the second poppet 5 is blocked by the on / off spool 6 so as not to flow, leakage of oil through the second poppet 5 can be prevented.

Therefore, in the structure of the first and second poppets 4 and 5 installed in the above-described selector valve 8, leakage of hydraulic oil occurs due to a temperature increase when using an optional device requiring a relatively high pressure and a large capacity depending on the working conditions. It minimizes the pressure loss and prevents the durability of the low pressure option device with less internal allowable back pressure.

According to the preferred embodiment as described above has the following advantages.

Optionally installed at the tip of the excavator's working device prevents leakage due to the temperature rise from the select valve that controls the flow direction of the hydraulic oil supplied to the optional device operated at high pressure to secure a safe working environment to increase the reliability of the equipment Can be.

In addition, by simplifying the flow path formed inside the select valve to reduce the size of the corresponding parts, it is possible to significantly improve the durability of the option device by reducing the pressure loss.

The embodiments as described above are intended to be described in detail so that those skilled in the art of heavy equipment can be easily carried out, and thus, a part of the technical contents are modified within the scope without departing from the technical spirit of the present invention. You can do it.

Claims (4)

Heavy equipment option equipped with a hydraulic pump, an optional device connected to the hydraulic pump to drive the hydraulic oil supply, and a main switching valve installed in the flow path between the hydraulic pump and the optional device to control the flow direction of the hydraulic oil supplied to the optional device. In the hydraulic circuit: A first poppet (4) installed to open and close the flow path between the main switching valve (1) and the option device (3), and blocking the flow path when the operating pressure of the option device (3) is low; Installed to open and close the flow path between the first poppet (4) and the option device (3), when the operating pressure of the option device (3) is low pressure, the downstream side is drained and the use of the option device (3) The second poppet (5) is installed to be seated when the pressure is high pressure; And It is installed in the flow path between the downstream side of the second poppet (5) and the tank, the operating oil discharged from the option device (3) by draining the downstream side of the second poppet (5) by operating when supplying a signal pressure from the outside Hydraulic circuit for heavy equipment option, characterized in that it comprises an on / off spool (6) for returning the tank to the tank. 2. The device of claim 1, wherein when the operating pressure of the option device is low, the option device 3 is removed from foreign matter contained in the hydraulic oil returned from the option device 3 through the second poppet 5. Hydraulic circuit for heavy equipment option device characterized in that it comprises a filter (10) installed in the return flow path to protect. The heavy equipment option according to claim 1, further comprising a solenoid valve (7) which switches upon application of an electrical signal by a pedal or a remote control valve by a driver to supply an operating pressure to the on / off split (6). Hydraulic circuit for the device. According to claim 1, When the operating pressure of the option device 3 is a high pressure, forming a boundary between the high pressure working oil and the low pressure drain side to prevent leakage through the first poppet (4) Hydraulic circuit for heavy equipment option device characterized in that it comprises a sealing (11) mounted to the sliding portion of the one poppet (4).