KR20100028322A - Control valve spool structure for for heavy construction equipment - Google Patents

Abstract

PURPOSE: A spool structure of a control valve for heavy construction equipment is provided to improve equipment operation and valve response by reducing flow force generated in a spool notch. CONSTITUTION: A spool structure of a control valve for heavy construction equipment comprises a valve block and a spool(2). The spool is switched by pilot pressure, applied to a pilot pressure supply port formed in one side of the valve block. When the spool is switched, fluid, discharged from a pump port, is supplied to a cylinder chamber. The fluid operates a cylinder, and is returned to a hydraulic tank.

Description

CONTROL VALVE SPOOL STRUCTURE FOR FOR HEAVY CONSTRUCTION EQUIPMENT}

The present invention relates to a control valve spool structure for construction equipment, and more particularly, to offset the flow force generated in the spool notch during the switching of the spool so that the spool stroke is controlled in accordance with the pilot pressure change in the initial section The present invention relates to a control valve spool structure for construction equipment which is improved to significantly increase linear flow control and valve responsiveness in a control valve.

In general, in construction equipment such as excavators, work tool actuators including boom actuators, arm actuators, and bucket actuators for adjusting work tools use control valves for respective work actuators which are supplied with a flow rate from a hydraulic pump. Each control valve can control the operation of the boom cylinder, the arm cylinder and the bucket cylinder when the flow rate discharged from the hydraulic pump returns to the hydraulic tank through the spool notch.

In general, the pilot pressure for controlling the spool switching installed in the control valve should take into account the elastic force of the spring supporting the spool inside the spool cap of the control valve and the flow force due to the flow rate through the outlet of the notch when the spool is switched. .

The flow force (F) on the notch of the spool is defined as "F = ρQVcosθ", where ρ is the density of the fluid, Q is the flow rate, V is the velocity of the fluid, and θ is the angle of fluid flow at the notch outlet. Indicates. Since the velocity of the fluid increases as the cross-sectional area of the notch increases, the flow force changes according to the increase in the flow rate and the switching amount of the spool. Therefore, the flow control and the driving performance control of the actuator for the working device in consideration of the flow force during the switching of the spool It is difficult and the operation performance of work tools and equipment is also greatly influenced by the flow force.

1 is a view schematically showing a conventional control valve for heavy equipment, Figure 2 is an enlarged view of the portion of "A" shown in Figure 1 is a schematic view showing a conventional spool structure.

Typically, the spool 2 installed in the valve block 1 for controlling the driving of the cylinder for the work device is switched to the left and right sides with reference to the drawings by a pilot pressure input from the outside.

For example, when the pilot pressure supplied to the pilot supply port 15 overcomes the elastic force of the spring 14 against the pilot pressure inside the spool cap 16, the spool 2 is switched to the left in the drawing. . At this time, the flow rate discharged from the hydraulic pump to the pump port (3) pushes the rod check poppet (4) and passes through the supply side spool notch (6) and the supply passage (7) through the parallel passage (5) cylinder for the work machine It is supplied to the large chamber 8a.

The flow rate of operating the cylinder and returning it is returned to the hydraulic tank from the cylinder small chamber 8b for the work device through the return flow path 9 through the return side spool notch 10, the regeneration flow path 11, and the tank path 12. do.

At this time, the flow force generated in the spool notches 6 and 10 is generated in the opposite direction to the spool moving direction by the flow of the flow rate passing through the spool notch when the spool 2 is switched.

In particular, when the hydraulic oil returns from the cylinder 8 side to the regeneration passage 11 and the tank passage 12 side by the switching of the spool 2 to the tank side, the flow force generated on the spool notch 10 is increased due to the increase in flow rate. Therefore, as the cross-sectional area of the notch increases and the speed increases, the cross-sectional area of the spool notch should be initially reduced as much as possible to suppress the speed change caused by the rapid flow inflow to maintain the control performance.

However, when the switching amount of the spool is small, that is, at the initial stage of the spool switching in which the cross-sectional area of the spool notch is formed, the flow force is increased due to the increase of the flow rate due to the reduction of the cross-sectional area of the spool notch. There was a problem that can not implement a linear control performance.

Referring to the pilot pressure change diagram for the spool stroke in spool switching shown in FIG. 3, the stroke St of the spool increases proportionally even if the pressure Pi for spool switching increases with respect to the pilot pressure acting on the spool. Nonlinear interval St-1 occurs.

In this section St-1, even if the pilot pressure Pi overcomes the elastic force of the spring 14 of the spool, the flow force F is spooled in the same direction as the elastic force by the pressure oil passing by the structure of the notch. 2) Pressurized, and ultimately, in order to properly control the switching of the spool, it means that the pilot pressure Pi should be set in consideration of the flow force F as well as the elastic force of the spring.

If the flow force (F) is increased in the excavator or heavy construction equipment that requires a large flow rate, the spool of the corresponding control valve does not move smoothly even if the operator's work device is operated. No, there was a problem that the equipment operability and valve responsiveness is greatly reduced.

In addition, as the equipment operability and valve responsiveness are deteriorated, there is a problem of causing fatigue of the operator when operating the equipment for a long time, as well as fuel efficiency and work efficiency.

The present invention has been made to solve the above-mentioned conventional problems, to provide a control valve spool structure for construction equipment that can improve the equipment operability and valve response by structurally reducing the flow force generated in the spool notch. The purpose is.

The present invention was created to solve the conventional problems,

A valve block;

And a spool switched by pilot pressure introduced into a pilot pressure supply port formed at one side of the valve block.

When the spool is switched, the flow rate discharged from the pump port pushes the rod check poppet, passes through the parallel flow path, passes through the supply side spool notch and the supply flow path, and is supplied to the cylinder large chamber for the working device. In the control valve spool structure for heavy equipment installed in the control valve for heavy equipment returned to the hydraulic tank through the return side spool notch, regeneration flow path and the tank passage from the small cylinder chamber for

A spool neck extending from one end of the spool notch, having a groove formed to have an inclination from an outer circumference of the spool, and configured to be adjacent to the return flow path;

And an inclined notch extending from the other end of the spool notch, the groove being formed to have an inclination from the outer circumference of the spool and configured to be adjacent to the regeneration flow passage. do.

The spool neck is provided with a spool neck bottom inclined at an angle of 10 ° to 15 ° from the outer circumference of the spool and a spool neck inclined portion at an angle of 55 ° to 65 ° from the outer circumference of the spool, The spool neck inclination portion is extended to one end of the spool notch characterized in that the control valve spool structure for heavy equipment construction.

Preferably the spool neck bottom portion is formed at an angle of 12.8 °, the spool neck inclined portion is characterized in that the control valve spool structure for construction equipment made of 60 ° angle.

In addition, according to another embodiment of the present invention, the control valve spool for construction equipment is formed by forming the inclined notch groove in the first inclined notch adjacent to the spool neck and the second inclined notch connected to the first inclined notch. It is characterized by a structure.

The first inclined notch is grooved at an angle of 15 ° to 25 °, and the second inclined notch is grooved at an angle of 40 ° to 50 °.

Preferably, the first inclined notch is formed in the groove at an angle of 20 °, the second inclined notch is characterized in that the control valve spool structure for construction equipment consisting of a groove formed at an angle of 45 °.

In addition, according to another embodiment of the present invention, the spool neck inclined portion is formed to extend below the one end of the notch, characterized in that the control valve spool structure for construction equipment formed by forming an adjacent groove.

The spool neck bottom extending on one side of the groove is characterized in that the control valve spool structure for construction equipment made of an inclined surface in the range of 5 ° to 9 ° angle from the outer periphery of the spool.

According to the present invention, when the spool is switched, the spool notch is opened in response to the pilot pressure change in the initial section, thereby enabling linear flow rate control in the control valve for the work device and at the same time, the valve responsiveness is greatly increased.

In addition, by reducing the flow force generated when the hydraulic oil returned from the actuator for the work device including the boom or the arm passes through the spool notch, it maintains the optimum flow control performance in the control valve and prevents driver fatigue and fuel economy. There is a merit that the improvement and work efficiency are greatly increased.

Hereinafter, with reference to the accompanying drawings will be described the configuration and effect according to an embodiment of the present invention. 4 is a partially enlarged view of a control valve spool structure for construction equipment according to an embodiment of the present invention, Figure 5 is a partially enlarged view of a control valve spool structure for construction equipment according to another embodiment of the present invention, Figure 6 Partial enlarged view of a control valve spool structure for construction equipment according to another embodiment of the invention, Figure 7 is a pilot pressure-spool stroke for explaining the offset action of the flow force by the control valve spool structure for construction equipment according to the present invention This is a state diagram.

In the description of the embodiment of the present invention, reference numeral 1 is a valve block, 2 is a spool, 5 is a pump port through which hydraulic oil is discharged from a hydraulic pump, 5 is a parallel flow path, and 7 is a cylinder large chamber 8a side. 9 is a return flow path through which a flow rate is introduced from the cylinder small chamber 8b, 11 is a regeneration path, 12 is a tank path, an elastic member against 14 pilot pressures, and 16 is a spool cap. .

Control valve spool structure for construction equipment according to an embodiment of the present invention,

A valve block 1;

And a spool (2) switched by a pilot pressure introduced into a pile pressure supply port (15) formed at one side of the valve block (1).

When the spool 2 is switched, the flow rate discharged from the pump port 3 pushes the rod check poppet 4 and passes through the supply side spool notch 6 and the supply channel 7 via the parallel channel 5. The flow rate supplied to the cylinder large chamber 8a for the device and operating and returning the cylinder 8 is returned from the cylinder small chamber 8b for the working device via the return flow path 9 to the return side spool notch 18 and the regeneration flow path. (11) and the control valve spool structure for heavy equipment installed in the control valve for heavy equipment returned to the hydraulic tank through the tank passage (12),

A spool neck 19 extending from one end of the spool notch 18 and having a groove formed to be inclined from an outer circumference of the spool 2 and configured to be adjacent to the return flow path 9;

An inclined notch 20 extending from the other end of the spool notch 18 and having a groove formed to have an inclination from the outer circumference of the spool 2 and configured to be adjacent to the regeneration flow passage 11. It is configured by.

The spool neck 19 is inclined at an angle of 10 ° to 15 ° from the outer circumference of the spool 2 and the spool neck bottom 19a and 55 ° to 65 ° from the outer circumference of the spool 2. It is provided with a spool neck inclined portion 19b inclined at an angle, wherein the spool neck inclined portion 19b extends at one end of the spool notch 18.

The spool neck bottom 19a and the spool neck inclined portion 19b are cylinder small chambers through the return flow path 9 when the spool 2 is switched to the left in the drawing when the pilot pressure is introduced to the pilot port 15. (8b) to guide the pressure oil returned to the regeneration passage (11), and at the same time the flow pressure is reduced by passing the cross-sectional area of the spool neck bottom 19a and the spool neck inclined portion (19b) flow force Perform the function of offsetting.

Preferably, the spool neck bottom portion is formed at an angle of 12.8 degrees, and the spool neck inclination portion is preferably configured at an angle of 60 degrees.

According to another embodiment of the present invention, as shown in FIG. 5, the inclined notch 20 is connected to the first inclined notch 21 and the first inclined notch 21 adjacent to the spool neck 19. It is made by forming a groove on the second inclined notch 22 to be connected. In this case, the second inclined notch 22 is formed adjacent to the regeneration flow passage 11.

In addition, the first inclined notch 21 is inclined at an angle of 15 degrees to 25 degrees, and the second inclined notch 22 is inclined at an angle of 40 degrees to 50 degrees. Preferably, the first inclined notch 21 is formed at an angle of 20 degrees with respect to the outer circumference of the spool 2, and the second inclined notch 22 is formed of a recess formed at an inclination angle of 45 degrees. .

The first inclined notch 21 and the second inclined notch 22 have a cylinder small through the return flow path 9 when the spool 2 is switched to the left in the drawing when the pilot pressure is introduced into the pilot port 15. The pressure oil returned from the chamber 8b is guided to the regeneration passage 11, and at the same time, the pressure oil returned is reduced by passing the cross sectional area of the first inclined notch 21 and the second inclined notch 22. Function to offset the flow force.

Meanwhile, according to another embodiment of the present invention, as shown in FIG. 6, the spool neck inclined portion 19b extends below one end of the notch 18 and forms an adjacent groove 24. It is done by At this time, the spool neck bottom 19b extending on one side of the groove 24 forms an inclined surface in the range of 5 ° to 9 ° from the outer circumference of the spool 2. In this case, the groove 24 is disposed below the notch 18 and configured to be adjacent to the regeneration passage 11.

The groove 24 is a passage for regenerating pressure oil returned from the cylinder small chamber 8b through the return passage 9 when the spool 2 switches to the left in the drawing when the pilot pressure is introduced to the pilot port 15. At the same time, the function of guiding to (11) is carried out, and at the same time, the returning oil passes through the cross-sectional areas of the spool neck 19 and the groove 24 to reduce the speed to cancel the flow force.

When the inclined notch 20, the first inclined notch 21, the second inclined notch 22 and the groove 24 according to the embodiment of the present invention are configured adjacent to the spool neck 19, end milling It is preferable to manufacture by a process.

The control valve spool structure for construction equipment according to the present invention configured as described above passes the return side spool notch 18 through the return flow path 9 from the cylinder small chamber 8b for the working device and the flow rate returned to the work device. In this case, it was found that the flow force acting in the opposite direction to the pressure applied at the pilot pressure supply port 15, in particular, the flow force largely generated at the time of switching of the spool 2 was greatly canceled.

That is, in the related art, the spool stroke is fixed to S1 even when the spool 2 is changed to pilot pressures P1 and P2 during the switching of the spool 2 due to the flow force acting in the opposite direction to the pilot pressure in the spool notch. There was a problem in that the control was difficult and the response of the control valve for the work device such as the boom or the arm was greatly reduced. However, according to the present invention, the flow force is the spool notch 18, the inclined notch 20, and the spool neck 19. When the spool 2 is supplied to the spool 2 from the pilot pressure P1 of the initial section during the switching of the spool 2 by the offset through the structure of the spool 2, the spool stroke St is switched from S1 to S2 corresponding to the pilot pressures P1 and P2. Opening the spool notch allows linear flow control at the control valve for the work tool and at the same time, responsiveness is significantly increased (see FIG. 7).

In the description of the present invention, although the spool 2 is switched, the spool notch 18 and the inclined notch 20, the first inclined notch 21, the second inclined notch 22, and the groove 24 according to the invention. ), The return flow path from the return flow path 9 to the regeneration flow path 11 and the tank path 12 through the configuration of the bottom portion 19a of the spool neck 19 and the inclined portion 19b of the spool neck 19. Although described on the basis of the flow to the side, various geometrical modifications are possible depending on the switching direction of the spool 2 and the magnitude of the required flow rate, and those skilled in the art can include such modifications in the technical spirit described in the claims of the present invention. It will be understood that.

1 is a cross-sectional view of a control valve for construction equipment for explaining a conventional control valve spool structure for construction equipment,

FIG. 2 is a partially enlarged view of a portion “A” shown in FIG. 1 in which a spool notch acting on a return flow path by a control valve spool structure for construction equipment;

3 is a pilot pressure-spool stroke operating state diagram for explaining the action of the flow force by the conventional spool structure,

Figure 4 is an enlarged partial view of the control valve spool structure for construction equipment according to an embodiment of the present invention,

5 is an enlarged partial view of a control valve spool structure for construction equipment according to another embodiment of the present invention,

Figure 6 is an enlarged partial view of the control valve spool structure for construction equipment according to another embodiment of the present invention,

7 is a pilot pressure-spool stroke action state diagram for explaining the offset action of the flow force by the control valve spool structure for construction equipment according to the present invention,

<Description of the symbols for the main parts of the drawings>

1: valve block

2: spool

3: pump port

5: parallel euros

7: supply path

9: return euro

11: Regeneration Path

12: tank passage

13, 15: pilot pressure supply port

14: elastic member

16: Spool Cap

Claims (8)

A valve block; And a spool switched by pilot pressure introduced into a pilot pressure supply port formed at one side of the valve block. When the spool is switched, the flow rate discharged from the pump port pushes the rod check poppet, passes through the parallel flow path, passes through the supply side spool notch and the supply flow path, and is supplied to the cylinder large chamber for the working device. In the control valve spool structure for heavy equipment installed in the control valve for heavy equipment returned to the hydraulic tank through the return side spool notch, regeneration flow path and the tank passage from the small cylinder chamber for A spool neck extending from one end of the spool notch, having a groove formed to have an inclination from an outer circumference of the spool, and configured to be adjacent to the return flow path; An inclined notch extending from the other end of the spool notch, having a groove formed to have an inclination from the outer periphery of the spool, and configured to be adjacent to the regeneration flow path. rescue. The method according to claim 1, The spool neck is provided with a spool neck bottom inclined at an angle of 10 ° to 15 ° from the outer circumference of the spool and a spool neck inclination inclined at an angle of 55 ° to 65 ° from the outer circumference of the spool. Control valve spool structure for heavy equipment, characterized in that the spool neck inclined portion is formed extending from one end of the spool notch. The method according to claim 2, The spool neck bottom portion is formed at an angle of 12.8 °, the spool neck slope is a control valve spool structure for construction equipment, characterized in that the groove is formed at an angle of 60 °. The method according to claim 1, And a second inclined notch connected to the first inclined notch adjacent to the spool neck and a second inclined notch connected to the first inclined notch. The method according to claim 4, The first inclined notch is grooved at an angle of 15 ° to 25 °, and the second inclined notch is formed in a groove at an angle of 40 ° to 50 °. The method according to claim 5, The first inclined notch is formed in a groove at an angle of 20 °, the second inclined notch is formed in a groove at a 45 ° angle control valve spool structure for construction equipment. The method according to claim 2 or 3, And a spool neck inclined portion extending below one end of the notch and forming an adjacent groove. The method according to claim 7, The control valve spool structure for heavy equipment, characterized in that the spool neck bottom extending on one side of the groove has an inclined surface in the range of 5 ° to 9 ° angle from the outer periphery of the spool.

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