KR20230143018A - a safety lock valve including a logic valve capable of controlling the supply of pilot pressure - Google Patents

Abstract

In the present invention, a main flow path is formed to allow hydraulic oil to flow between a cylinder unit for operating the boom and an operation unit for operation, an auxiliary flow path connected in parallel with the main flow path is formed, and a safety lock connected to the pilot line and the drain line. A valve comprising: a main spool installed in the main passage to control opening and closing of the main passage; A relief valve installed in the main flow path and opened when the pressure exceeds a set level; an orifice valve installed in the main flow path to control the main spool by discharge pressure from the surge pressure of the relief valve; A logic valve is installed in the auxiliary passage and opens the auxiliary passage from the main passage using pilot pressure. A safety lock valve is provided.

Description

Safety lock valve including a logic valve capable of controlling the supply of pilot pressure}

The present invention relates to a safety lock valve containing a logic valve capable of controlling pilot pressure supply, and is a technology that improves safety and operational responsiveness by lowering the boom of construction equipment.

In general, construction equipment handles heavy objects or generates large forces to perform excavation work, and uses hydraulic devices as a source of power. Since the development of the first construction equipment, there has been a continuous demand for smaller, higher-pressure devices to improve work capacity, and as a result, the risk of rupture of pipes or rubber hoses, which are means of transporting hydraulic oil, has significantly increased.

The rupture of such pipes or rubber hoses leads to loss of function of the control valve, and when such an accident occurs when handling heavy materials, it results in a secondary major accident. Therefore, despite the sudden loss of hydraulic oil pressure due to pipe rupture, etc., the cylinder A safety device that stops the operation of the equipment or slows it down by closing the connection port is essential.

As an example of a safety device, a lock valve is used. Republic of Korea Patent No. 10-0701031 "Excavator boom emergency lowering device" includes a hydraulic oil line (20) according to the boom down on the cylinder that operates the boom. Technology is applied to prevent the excavator's bucket from descending at high speed by installing a check valve. However, the safety lock valve is a type of safety device that is directly connected to the connection port of the hydraulic cylinder and performs the function of closing the connection port in the event of sudden loss of hydraulic oil. However, the hydraulic oil passing through the control valve inevitably experiences a pressure drop. occurs, which results in a decrease in the controllability of the equipment or a decrease in digging force or traction force.

Another example of a lock valve is disclosed in Republic of Korea Registration No. 10-2263246, “Excavator boom/arm emergency lowering device with safety lock function incorporating logic valve.” In conventional lock valves, the logic valve has a structure that gradually opens the pilot pressure in proportion to the pressure of the cylinder. Since the pilot pressure must be adjusted according to changes in cylinder pressure, there has been a problem of somewhat poor operation response.

KR 10-0701031 B1 “Excavator boom emergency lowering device” KR 10-2263246 B1 "Excavator boom/arm emergency lowering device with safety lock function incorporating logic valve"

In order to solve the above problems, the present invention provides a logic valve capable of controlling pilot pressure supply that can improve operational responsiveness to boom down by operating immediately at the pilot set pressure regardless of the pressure applied to the cylinder of construction equipment. The purpose is to provide a safety lock valve that contains

In order to solve the above problems, the present invention is to form a main flow path so that hydraulic oil flows between a cylinder unit for boom operation and an operation unit for operation, an auxiliary flow path connected in parallel with the main flow path is formed, and a pilot line and a safety lock valve connected to a drain line, comprising: a main spool installed in the main flow passage to control opening and closing of the main flow passage; A relief valve installed in the main flow path and opened when the pressure exceeds a set level; an orifice valve installed in the main flow path to control the main spool by discharge pressure from the surge pressure of the relief valve; A logic valve installed in the auxiliary passage to open the auxiliary passage from the main passage using pilot pressure. A safety lock valve including a logic valve capable of controlling pilot pressure supply is provided.

The logic valve includes a first logic valve installed between the main flow path and the auxiliary flow path to open and close, and a second logic valve connected to the first logic valve and operating the opening and closing of the first logic valve by pilot pressure. It is characterized by being composed of.

The first logic valve includes an external poppet that is installed between the main flow path and the auxiliary flow path and opens when the set pressure is reached, and an external poppet that is installed inside the external poppet and opens when the set pressure is reached to control the internal pressure of the external poppet. It is characterized in that it consists of an internal poppet that is removed.

The second logic valve is installed with a pilot poppet that is connected to the pilot line and opens by pilot pressure to transmit pressure to the first logic valve to open, and a check valve that blocks and discharges the pilot pressure. It is characterized by

The second logic valve is characterized in that a spring rod is installed between the pilot poppet and the first logic valve to transmit pilot pressure.

According to the above solution, the following effects can be expected.

First, even if the cylinder pressure changes when the boom/arm of construction equipment is lowered, the boom/arm operates when the pilot set pressure is reached, thereby ensuring reliability of operation.

It has the effect of preventing pressure loss of hydraulic oil by sequentially opening the logic valves using pilot pressure.

Figure 1 is a configuration diagram of a conventional excavator boom emergency lowering device.
Figure 2 is an overall configuration diagram of a safety lock valve including a logic valve capable of controlling pilot pressure supply according to an embodiment of the present invention.
Figure 3 is a cross-sectional view taken along line B-B' in Figure 2.
FIG. 4 is a cross-sectional view taken along line A-A' of FIG. 2.
Figure 5 is a hydraulic circuit diagram of Figure 2.
Figure 6 is a logic valve operation state diagram of a safety lock valve including a logic valve capable of pilot pressure supply control according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The following description and the accompanying drawings are presented for a general understanding of the present invention, and the technical scope of the present invention is not limited thereto. In addition, detailed descriptions of well-known structures and functions that may unnecessarily obscure the gist of the present invention will be omitted.

FIG. 2 is an overall configuration diagram of a safety lock valve including a logic valve capable of controlling pilot pressure supply according to an embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line B-B' of FIG. 2, and FIG. 4 is a cross-sectional view of FIG. 2. This is a cross-sectional view of A-A'.

Referring to Figures 2, 3, and 4, the safety lock valve containing a logic valve capable of controlling pilot pressure supply according to the present invention is largely divided into a main spool (100), a relief valve (200), an orifice valve (300), and a logic valve (400). ) can be seen to be included.

Figure 5 is a hydraulic circuit diagram of Figure 2.

In Figure 5, C2 is the connection port of the cylinder unit, V2 is the connection port of the operation unit, and E is a port used only when connecting multiple cylinders and is connected to maintain pressure balance with other cylinders. Pil shown in the drawing is a pilot port that supplies pressure for valve switching of the main spool 100 of the lock valve, and T is a drain port.

In the present invention, the safety lock valve containing a logic valve capable of controlling pilot pressure supply has a main flow path (L1) formed so that hydraulic oil flows between a cylinder unit for boom operation and an operation unit for operation, and the main flow path (L1) ) is formed in parallel with the auxiliary passage (L2) and is connected to the pilot line (P1) and the drain line (T1).

The main spool 100 is installed in the main passage (L1) to control the opening and closing of the main passage (L1) and the auxiliary passage (L2).

Here, the main spool 100 has a built-in check valve, and hydraulic oil is supplied through the control valve by operating the joystick of the operating unit.

When the boom is operated, it passes through the main spool (100) from the V2 port and flows into the C2 port to be supplied to the cylinder unit.

Conversely, in the case of boom down, pilot pressure is supplied and hydraulic oil moves from the C2 port to the V2 port by changing direction by the main spool 100.

The relief valve 200 is installed in the main flow path (L1) and connected to the pilot port through the orifice valve 300. Here, the relief valve 200 is connected to the main flow path (L1) and can protect against surge pressure by regulating the maximum pressure.

The orifice valve 300 is installed between the main spool 100 and the pilot line (P1), and when a pressure higher than the maximum pressure regulation is generated from the relief valve 200, some of the pressure is relieved and the remaining pressure is released through the orifice valve 300. The main spool 100 is controlled using pressure as pilot pressure.

The logic valve 400 is installed in the auxiliary passage (L2) and opens the auxiliary passage (L2) from the main passage (L1) using pilot pressure.

The logic valve 400 can ensure stability by preventing rapid descent, especially in the case of a boom down, and in the present invention, the reliability of operation is improved by speeding response especially with the pilot set pressure. The main gist of the present invention is to secure.

Here, the logic valve 400 is connected to the first logic valve 420, which is installed between the main flow path (L1) and the auxiliary flow path (L2) and opens and closes, and is connected to the pilot pressure. It consists of a second logic valve 440 that operates to open and close the first logic valve 420.

In detail, the first logic valve 420 is installed between the main flow path (L1) and the auxiliary flow path (L2) and has an external poppet 422 that opens when the set pressure is reached, and an external poppet 422 inside the external poppet 422. It is composed of an internal poppet 424 that is opened when installed and reaches the set pressure to remove the internal pressure of the external poppet 422. The first logic valve 420 is formed as a double check valve.

The second logic valve 440 is connected to the pilot line (p1) and opens by pilot pressure, and transmits pressure to the first logic valve 420 to open the first logic valve 420. A pilot poppet 442 and a check valve 444 that block and discharge the pilot pressure are installed. Here, the pilot set pressure can be designed by the spring pressure of the pilot poppet 442, and in the present invention, it is set to a pressure of about 27 bar to operate. The pressure can be freely set depending on the usage environment.

In addition, the second logic valve 440 is characterized by a spring rod 460 installed between the pilot poppet 442 and the first logic valve 420 to transmit pilot pressure. The spring rod 460 has a spring installed in the rod, and the rod is moved to the first logic valve by pilot pressure and restored by the elasticity of the spring.

Below, the operation of the logic valve will be described.

Figure 6(a) is a hydraulic oil flow chart of the logic valve in a neutral state.

Referring to FIG. 6(a), the pressure of hydraulic oil in the main flow path is lower than the set pressure of the first logic valve 420 and is not opened. At this time, the external poppet 422 has a connection hole formed on the side to allow external hydraulic oil to move to the internal pressure chamber, and an internal poppet 424 is formed in the internal pressure chamber and is pressured by the inflow hydraulic oil.

Referring to FIG. 6(b), when pilot pressure is input through user manipulation, the pilot poppet 442 is opened in the second logic valve 440. Then, by pressing the spring rod 460, the internal poppet 424 moves backwards, opening the auxiliary passage, blocking the inflow into the internal pressure chamber, and discharging the fluid to the external auxiliary passage.

Referring to FIG. 6(c), the external poppet 422 is moved backward by the spring rod 460, opening the auxiliary passage, and hydraulic oil is discharged from the external pressure chamber.

Referring to FIG. 6(d), when the pilot pressure is blocked, fluid flows out to the check valve 444, and the first logic valve 420 is closed by the pressure of the hydraulic oil.

Therefore, the first logic valve 420 can be opened by first opening the internal poppet 424 using the pilot set pressure to remove the pressure in the internal pressure chamber and then opening the external poppet 422 secondarily.

In the present invention, when the pilot set pressure is exceeded, the first logic valve 420 can be opened to V2. Therefore, even if the cylinder pressure changes, it can be opened at the pilot set pressure, ensuring reliability of operation.

As described above, it can be seen that the present invention is based on the technical idea of a safety lock valve containing a logic valve capable of pilot pressure supply control, and within the scope of the basic idea of the present invention, common knowledge in the art Of course, many other transformations are possible for those who have.

100: main spool
200: relief valve
300: Orifice valve
400: Logic valve
420: First logic valve
422: External poppet
424: Internal poppet
440: Second logic valve
442: Pilot poppet
460: spring load

Claims (5)

A main flow path is formed to allow hydraulic oil to flow between a cylinder unit for boom operation and an operation unit for operation, an auxiliary flow path connected in parallel with the main flow path is formed, and a safety lock valve is connected to the pilot line and the drain line. ,
A main spool installed in the main flow path to control opening and closing of the main flow path;
A relief valve installed in the main flow path and opened when the pressure exceeds a set level;
an orifice valve installed in the main flow path to control the main spool by discharge pressure from the surge pressure of the relief valve;
A logic valve installed in the auxiliary passage to open the auxiliary passage from the main passage using pilot pressure;
A safety lock valve containing a logic valve capable of pilot pressure supply control, characterized in that it is included. According to paragraph 1,
The logic valve is,
A first logic valve installed between the main flow path and the auxiliary flow path to open and close,
A safety lock valve containing a logic valve capable of controlling pilot pressure supply, characterized in that it is connected to the first logic valve and consists of a second logic valve that opens and closes the first logic valve by pilot pressure. According to paragraph 2,
The first logic valve is,
An external poppet that is installed between the main flow path and the auxiliary flow path and opens when the set pressure is reached,
A safety lock valve containing a logic valve capable of controlling pilot pressure supply, characterized in that it consists of an internal poppet that is installed inside the external poppet and opens when the set pressure is reached to remove the internal pressure of the external poppet. According to paragraph 3,
The second logic valve is,
Pilot pressure supply, characterized in that a pilot poppet is connected to the pilot line and opens by pilot pressure to transmit pressure to the first logic valve to open, and a check valve to block and discharge the pilot pressure. Safety lock valve containing a controllable logic valve. According to paragraph 4,
In the second logic valve,
A safety lock valve containing a logic valve capable of controlling pilot pressure supply, characterized in that a spring rod is installed between the pilot poppet and the first logic valve to transmit pilot pressure.