KR20120072519A

KR20120072519A - Flow variable controller apparatus

Info

Publication number: KR20120072519A
Application number: KR1020100134300A
Authority: KR
Inventors: 여명구; 이상우
Original assignee: 두산인프라코어 주식회사
Priority date: 2010-12-24
Filing date: 2010-12-24
Publication date: 2012-07-04
Also published as: KR101704042B1

Abstract

The present invention relates to a variable flow control device, and more particularly to a variable flow control device that can appropriately reduce the flow rate supplied to the work machine through the auxiliary pilot signal pressure irrespective of the pressure in the parallel passage. A pilot piston slid toward the poppet under signal pressure and a piston below it, and an annular pressure portion formed around the pilot piston and connected through the parallel passage and the flow path, is disclosed. By forming the cross section the same size as the lower cross section of the poppet, it provides a variable flow control device with a simple structure that can control the amount of movement (control amount) of the poppet irrespective of the pressure of the hydraulic oil in the parallel passage, and because of this simple structure Easy to manufacture, low manufacturing cost, and high dynamic characteristics Which can provide a variable flow rate control device.

Description

Flow variable controller apparatus

The present invention relates to a variable flow control device, and in particular, it is possible to appropriately reduce the flow rate supplied to the work machine through the auxiliary pilot signal pressure provided to the variable flow control device corresponding to the work machine regardless of the pressure in the parallel passage. The present invention relates to a variable flow control device.

When the main pump and the multiple work machines are connected through corresponding multiple directional selector valves and the two or more work machines are driven in combination, in order to increase the flow rate of the working oil for a specific work machine requiring a heavy load, A variable flow rate control device is disclosed that can receive a pilot signal pressure and control it to reduce the supply flow rate of hydraulic oil to the work machine to which it is connected.

Such a variable flow control device is basically arranged between a pump and a predetermined work machine, the direction switching valve for controlling the start, stop and direction switching of the work machine by switching the spool when the pilot signal pressure is applied, and the direction switching valve. A poppet disposed with respect to the parallel passage in the housing of the housing and the auxiliary pilot signal pressure to move the poppet to at least partially close the connection between the parallel passage and the left and right pair of cylinder flow paths to control the flow rate supplied to the work machine. Reducing) flow control valve means.

In this arrangement, the control of the actual flow rate can be indicated according to the result of the sum of the action forces acting in the device, specifically the poppet, which acts as an auxiliary pilot signal pressure, the pressure of the hydraulic fluid in the parallel passage, and The pressure can be compounded by a number of pressure chambers, a number of spring forces contained therein, and the like, that provide a pressure to generate a real action force for each component.

For example, Figure 1 is a cross-sectional view showing an example of a conventional hydraulic control device, the hydraulic control device 10 according to Figure 1 receives the pilot signal pressure, the start, stop, In addition to the direction switching valve 20 capable of controlling the direction switching, a poppet 30 capable of opening and closing the connection between the parallel passage 22 and the cylinder flow passage 24, and a poppet under the auxiliary pilot signal pressure And piston means (or 'flow control means') 40 capable of controlling the amount of movement of 30. In more detail, the poppet 30 is configured in the form of a double poppet in which the small poppet 34 is embedded in the large poppet 32, and the piston means 40 includes a pressure chamber (3) formed for the large piston 42. A pressure chamber 44a formed against 42a and the small piston 44 and a compensating pressure chamber 46a that counteracts the piston action force of the pressure chamber 44a of the small piston are formed on the upper portion of the extension piston 46. The pressure chamber 44a of the small piston communicates with the left and right cylinder flow passages 24 via the connecting portion 50.

In the hydraulic control device 10 of such a configuration, the pilot signal pressure transmitted from another work machine is transmitted to the pressure chamber 42a of the large piston 42 to generate an action force F1, and the pressure chamber 44a of the small piston 44. ), The pressure P1 of the cylinder flow path 24 or the pressure P of the parallel passage 22 is applied to generate an action force F3 acting on the small piston 44 and an action force F5 acting on the large poppet 32. In communication with the pressure chamber 44a of the small piston, an action force F4 offset from the action force F3 is generated in the compensation pressure chamber 46a. In addition, the action force F2 generated when opening the large poppet 32 may be substantially offset from the action force F5 generated in the pressure chamber 44a of the small piston 44. As a result, the amount of movement of the poppet 30 can be controlled by the action force F1 generated in the pressure chamber 42a of the large piston 42, which means that the amount of movement of the poppet 30-that is, the flow rate is controlled by the auxiliary pilot signal. It means that it can be controlled only by the action force F1 generated by the pressure.

However, in the structure of the prior art, in order to draw the above conclusions, a small poppet 34 is formed in the large poppet 32, and the opening 32b is formed in the tip portion 32a of the large poppet and then corresponds to the opening. To form the distal end portion 34a of the small poppet 34, communicate with the pressure chamber 44a of the small piston inside the small poppet 32, and communicate with the left and right cylinder flow passages 24. In addition, it is required that the connecting portion 50 which communicates the pressure chamber 44a of the small piston with the left and right cylinder flow passages 24 be formed. In addition, the diameters of the small piston 44 and the extending piston 46 must be the same, and a hollow (euro) 48 also penetrating the small piston 44, the large piston 42 and the extending piston 46 is also formed. Requires that it be

As described above, in the hydraulic control apparatus according to the prior art, in order to accurately design the amount of movement of the poppet (control amount of the working oil flow rate), a large and small double poppet and a connection portion communicating with the hollow, left and right cylinder flow paths formed therein are formed. In addition to the demands of the above, a complicated configuration is required such that the diameters of the small piston and the extension piston are the same, and a hollow is formed through the small piston and the large piston and the extension piston.

Therefore, the conventional hydraulic control device having such a complicated configuration is complicated to manufacture, and has a disadvantage in that the dynamic characteristics of the working oil flowing therein are degraded due to the complicated configuration. In addition, there is a disadvantage that the manufacturing cost is increased due to the complicated configuration.

SUMMARY OF THE INVENTION An object of the present invention is to provide a variable flow rate control device that is simple in construction and capable of simply designing a variable flow rate by an auxiliary pilot voltage.

It is also an object of the present invention to provide a variable flow control device having improved dynamic characteristics by applying a simple structure using a single poppet.

In addition, the present invention is to provide a variable flow control device having a low manufacturing cost by applying a simple structure.

The present invention is arranged between a pump and a predetermined work machine, and supplies a hydraulic oil into a housing of the direction change valve and a direction change valve for controlling the start, stop and direction change of the work machine by switching the spool when the pilot signal pressure is applied. A parallel passage, a poppet configured to open and close the parallel passage, and a flow control valve for controlling the opening and closing of the poppet when the auxiliary pilot signal pressure is applied, wherein the flow control valve is sealed to be fastened onto the housing portion where the poppet is formed. The main body is provided with a piston and a pilot piston which are arranged to be slidably vertically corresponding to the poppet, and a pilot port for guiding the auxiliary pilot signal pressure to the top of the pilot piston, and also directs the pilot piston toward the poppet. Annular pressure portion which can pressurize The cross-sectional area A 'of the annular pressure portion and the cross-sectional area A of the lower part of the poppet facing the parallel passage are identical, and the opening and closing degree of the poppet is parallel by connecting the annular pressure portion through the parallel passage and the flow path in the housing. It provides a variable flow control device that is controlled regardless of the pressure in the passage.

In addition, the present invention is characterized in that a poppet spring for elastically supporting the poppet in the direction toward the parallel passage is further formed in the housing, and a pilot spring for elastically supporting the pilot piston in the direction toward the pilot port is further formed in the body.

In addition, the present invention, the cross-sectional area of the pilot piston receiving the auxiliary pilot signal pressure Pi, S, the cross-sectional area of the lower piston a, the pressure formed in the space between the poppet and the piston P _A , the pressure in the parallel passage P _B , and When the sum of the forces by the springs is called F_spring, the force equation formed around the poppet is characterized by Equation 2 described later.

In addition, the present invention is characterized by constituting the cross-sectional area (a) of the lower part of the piston and the cross-sectional area (A) of the lower part of the poppet facing the parallel passage.

In addition, the present invention is characterized in that the cross-sectional area (a) of the lower part of the piston is configured to be larger than the cross-sectional area (A) of the poppet lower part facing the parallel passage.

According to the present invention, it is possible to provide a variable flow control device capable of simply designing a reduction in flow rate (movement amount of poppet) controlled by the auxiliary pilot voltage with a simple configuration.

In addition, according to the present invention, by applying a simple structure using a single poppet can provide a variable flow rate control device with improved dynamic characteristics.

In addition, according to the present invention, by applying a simple structure, it is possible to provide a variable flow control device having a low manufacturing cost.

1 is a cross-sectional view showing an example of a conventional hydraulic control device;
2 is a cross-sectional view of a variable flow control device according to an embodiment of the present invention;
3 is an enlarged cross-sectional view of a flow control valve portion of the variable flow control apparatus of FIG. 2;
4A is a cross-sectional view illustrating an example in which the poppet is operating without the auxiliary pilot signal pressure in the variable flow control device of FIG. 2;
4B is a cross-sectional view illustrating an example in which the poppet is operated under the auxiliary pilot signal pressure in the variable flow control device of FIG. 2; And
5 is a hydraulic circuit diagram showing a hydraulic drive system according to another embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described with reference to an accompanying drawing.

FIG. 2 is a cross-sectional view illustrating a variable flow control device according to an embodiment of the present invention, and FIG. 3 is an enlarged cross-sectional view showing a flow control valve in the variable flow control device of FIG. 2. The structure of the variable flow control apparatus 100 according to the present invention will be described with reference to FIGS. 2 and 3 as follows.

Variable flow control device 100 of the present invention is disposed between the pump and the work machine, the direction switching valve 110 for supplying the working oil to the work machine to start, stop and change the working machine, and the parallel in the direction switching valve 110 A poppet 130 formed in the passage 120 and a flow control valve 140 for moving the poppet 130 based on the auxiliary pilot signal pressure Pi. The housing 112 of the direction switching valve 110 includes a parallel passage 120, a pair of left and right cylinder flow passages 122 connected to the parallel passage 120, and a load selectively connected through the spool 114. Each of the load ports 126 is connected to the passage 124 and the work machine.

The spool 114 can slide left and right due to the pilot signal pressure applied from the left side and the elasticity of the spring 118 disposed on the right side, for example, when the spool 114 slides to the left side. The hydraulic oil supplied from the pump through the 120 is supplied to the corresponding work machine through the cylinder passage 122 on the left side, the load passage 124 on the left side, and the load port 126 on the left side, and at this time, the hydraulic oil in the cylinder passage on the right side. Is returned to the tank through the drain port (not shown). On the contrary, for example, when the spool 114 slides to the right side, the hydraulic oil supplied through the parallel passage 120 is connected to the cylinder passage 122 on the right side, the load passage 124 on the right side, and the load port 126 on the right side. The hydraulic fluid in the cylinder flow path on the left side is returned to the tank through the drain port (not shown).

On the other hand, the poppet 130 is formed in the connection portion between the parallel passage 120 and the cylinder flow passage 122, the poppet 130 is moved up and down based on the drawing of the hydraulic oil supplied through the parallel passage 120 The flow rate can be selectively controlled (reduced). It is the flow control valve 140 described above that controls the movement amount of the poppet 130. In addition, the poppet 130 has a poppet spring 152 disposed on a stepped portion formed in the poppet 130 and the housing 112 on the side facing the piston 144, the poppet spring 152 is a poppet ( 130 is elastically supported in the direction toward the parallel passage (120). The poppet spring 152 presses the poppet 130 toward the parallel passage 120 during non-operation such that the poppet 130 completely closes the connection between the parallel passage 120 and the left and right pair of cylinder flow paths 122. This closes the flow of hydraulic oil.

The flow control valve 140 of the present invention includes a body 142 that is sealingly fastened to a portion of the housing 112 in which the poppet 130 is formed, and the body 142 can slide vertically corresponding to the poppet 130. The piston 144, the pilot piston 146, and the pilot port 148 are sequentially formed in the direction facing the poppet. Pilot port 148 serves to guide the auxiliary pilot signal pressure Pi to the upper portion 146a of the pilot piston. In addition, the pilot piston 146 is disposed in the pilot spring 154 disposed on the stepped portion formed in the pilot piston 146 and the main body 142 on the side facing the piston 144, the pilot spring 154 is a pilot The piston 146 elastically supports in the direction toward the pilot port 148. The pilot spring 154 pressurizes the pilot piston 146 to the pilot port 148 when the auxiliary pilot signal pressure is not applied.

In addition, in the main body 142, an annular pressure unit 146b capable of pressing the pilot piston 146 in the direction toward the piston 144 is further formed along the circumference of the pilot piston, wherein the annular pressure unit 146b A cross-sectional area A 'and a cross-sectional area A of the lower portion of the poppet 130 facing the parallel passage 120 have the same value, and a flow path connecting the annular pressure portion 146b with the parallel passage 120 ( 150 is formed through the housing 112 and the main body 142, through which the opening and closing degree of the poppet 130 can be controlled in response to the auxiliary pilot signal pressure (Pi) irrespective of the pressure in the parallel passage (120). have.

That is, the annular pressure unit 146b connected to the parallel passage 120 through the flow path 150 in order to eliminate the pressure in the parallel passage 120 with respect to the movement amount (control amount) of the poppet 130. And the same size of the cross-sectional area A of the poppet lower portion facing the parallel passage 120 and the size of the cross-sectional area A 'of the annular pressure portion 146b around the pilot piston 146 to be the same. A pair of forces acting in opposite directions with respect to

An example in which a variable flow control device having such a structure operates in an actual hydraulic circuit will be described. 4A and 4B show examples of flow control valves and poppets that are changed depending on the presence or absence of the auxiliary pilot signal pressure Pi when the directional valve is operated under the pilot signal pressure, respectively.

4A shows the flow control valve 140 'with hydraulic oil pushing up the poppet 130' from the parallel passage 120 when the spool is driven (not shown) by pilot signal pressure. As the poppet 130 'rises up, the poppet spring 152' which is elastically supporting the poppet 130 'down (in the direction toward the parallel passage) is compressed, and thus due to the rise of the poppet 130' The parallel passage 120 and the pair of left and right cylinder flow paths 122 are completely opened. At this time, the rising range of the poppet 130 'may be limited by the upper end of the poppet contacting the stepped portion in the housing 112 in which one end of the poppet spring 152' is supported.

Meanwhile, in FIG. 4A, the force for pushing up the poppet 130 ′ is due to the pressure in the parallel passage 120. However, as described above, the parallel passage 120 has an annular pressure portion 146b around the pilot piston 146. Since it is connected through the flow path 150, it also acts from top to bottom of the poppet. Thus, the force that actually raises the poppet may be implemented by the difference between the poppet spring 152 'force that elastically supports the poppet 130 and the force of the pilot spring 154 that supports the pilot piston 146.

4B shows that when the spool is driven (not shown) by the pilot signal pressure, hydraulic oil pushes the poppet 130 ″ up from the parallel passage 120 and simultaneously receives the auxiliary pilot signal pressure Pi. Pilot piston 146 '' pushes down piston 144 '' and poppet 130 '', resulting in poppet 130 '' with parallel passageway 120 and a pair of left and right cylinder flow paths 122 Shows a flow control valve 140 " with an incomplete opening. As such, it can be seen that the flow amount of the hydraulic oil supplied to the work machine is reduced by controlling (reducing) the amount of movement (rising height) of the poppet by receiving the auxiliary pilot signal pressure Pi while the spool is operated.

In such a variable flow control device 100, the amount of movement of the poppet can be designed based on a plurality of pressures and hydraulic parts subjected to these pressures. For example, the auxiliary pilot signal pressure Pi supplied to the pilot port 148, the pressure in the space between the poppet 130 and the piston 144, and the hydraulic oil pressure supplied through the parallel passage 120, and these pressures Receiving hydraulic parts such as the cross section of the upper portion 146a of the pilot piston, the cross section of the annular pressure portion 146b, the cross section of the lower portion of the piston 144, and the cross section of the poppet lower portion facing the parallel passage 120. have.

Define the equation of force acting on the poppet to numerically represent the poppet's displacement. First, to find the force acting on the poppet, define the following for each element:

Auxiliary Pilot Signal Pressure: Pi

Pressure formed in the space between poppet 130 and piston 144: P _A

Pressure in parallel passage 120: P _B

Cross section of pilot piston 146 upper portion 146a: S

Cross-sectional area under the poppet 130 facing the parallel passage 120: A

Cross-sectional area of the annular pressure portion 146b: A '

Cross section area under piston 144: a

Sum of the force on each spring: F_spring

Here, the force applied to the spring may be distinguished with respect to the poppet spring 152 and the pilot spring 154, but is simply expressed as the sum thereof herein.

Using the above factors and definitions, the equation of the force acting on the poppet 130 is obtained as in Equation 1 below. Note that the annular pressure part 146b is connected to the parallel passage 120 through the flow path 150 and therefore has the same pressure P _B as the pressure in the parallel passage 120.

With respect to Equation 1, applying the fact that the cross-sectional area A 'of the annular pressure part 146b and the cross-sectional area A of the poppet lower portion facing the parallel passage 120 are the same according to the characteristics of the present invention. 2 can be obtained.

As a result, the term relating to the pressure P _B in the parallel passage 120 is canceled, so that the force acting on the poppet 130 is independent of the pressure in the parallel passage 120, ie, the pressure P _B of the hydraulic oil supplied from the pump. It can be easily controlled based on the pressure Pi.

In Equation 2, if the relationship between the cross-sectional area (a) of the lower portion of the piston 144 and the cross-sectional area (A) of the lower portion of the poppet 130 facing the parallel passage 120 is set as follows, a simpler equation may be obtained. .

For example, if the cross-sectional area (a) of the lower portion of the piston 144 is formed in the same size as the cross-sectional area (A) of the lower portion of the poppet 130 facing the parallel passage, the following equation (3) can be obtained.

In this case, since the P_spring value is a value determined by the spring constant, the force equation may be interpreted as a first-order equation with the auxiliary pilot signal pressure Pi as a variable.

In addition, the cross-sectional area (a) of the lower part of the piston may be formed to be larger than the cross-sectional area (A) of the lower part of the poppet facing the parallel passage.

As described above, the variable flow control apparatus of the present invention uses the auxiliary pilot signal pressure Pi while using a much simpler configuration to reduce the amount of movement of the poppet-that is, the flow rate of the hydraulic oil supplied to the work machine. It can be controlled, and by using a simple structure, it is easy to manufacture and the associated cost is lowered, and furthermore, the simple structure can exhibit excellent dynamic characteristics.

Next, FIG. 5 shows a hydraulic drive system 200 according to another embodiment of the invention. According to FIG. 5, the hydraulic drive system 200 of the present invention includes a plurality of work machines (specifically, driving these work machines, for example, the boom 212, the bucket 214, the travel motor 216, etc.). Hydraulic cylinders, etc.), and a pump 210 for supplying hydraulic oil to these working machines, and a plurality of directional control valves 222 and 224 disposed between the pump 210 and the working machines 212, 214, and 216. 226, such as a work machine control means is formed. In addition, these directional control valves are provided with pilot signal pressure through a control unit such as a joystick (not shown) to control the operation of each work machine, and the start, stop, and direction change of each work machine through each directional control valve. Can be implemented.

In the figure, reference numeral 202 designates a center bypass line, reference numeral 204 designates a parallel line, reference numeral 240 designates a relief valve, and reference numeral 250 designates a tank from which hydraulic oil is recovered.

In the hydraulic drive system 200, a flow control valve 230 is connected to the direction change valve 224 disposed corresponding to the bucket 214, and the direction change valve 224 and the flow control valve 230 are connected to each other. Are combined to form the variable flow control device 100 of the present invention. The flow control valve 230 is provided with a port (eg, pilot port 148 of FIG. 2) for receiving the auxiliary pilot signal pressure. Also, reference numeral 232 corresponds to the flow path 150 of FIG. 2.

Based on the hydraulic drive system 200, an example in which the variable flow control device 100 of the present invention is operated as follows.

For example, in the case where the boom and the bucket are driven in combination, when the load is required to drive the boom more than the bucket, the directional switch valves 222 and 224 are disposed corresponding to the boom 212 and the bucket 214. A signal is provided to drive each work machine (boom, bucket) simultaneously, with a portion of the pilot signal provided for the boom being further provided as an auxiliary pilot signal (Pi) for the bucket, which reduces the flow rate of the hydraulic fluid to the bucket As a result, this reduced flow is further provided to the boom, allowing the boom to be driven more preferentially than the bucket.

In addition, although the variable flow control valve 100 of this invention is shown in the state arrange | positioned corresponding to the bucket in FIG. 5, it is clear that this invention is not limited to this. That is, the variable flow control device of the present invention can be applied to any work machine such as a boom or a traveling motor, and not a bucket, and at the time of complex driving of two or more work machines based on the driving priority of each work machine or the driver's work command. By appropriately controlling (distributing) the flow rate of the working oil provided from the pump, the overall working effect can be enhanced.

In addition, since a variable flow control valve having a simple structure can be used, a system can be easily configured and a dynamic circuit can be improved as compared with the case of using a complicated component.

100: variable flow control device 110: directional control valve
112: housing 114: spool
116: pilot port 118: spring
120: parallel passage 122: cylinder flow path
124: load passage 126: load port
130: poppet 140: flow control valve
142: main body 142a: drain port
142b: tank 144: piston
146: pilot piston 146a: upper portion of the pilot piston
146b: annular pressure section 148: pilot port
150: Euro
200: hydraulic drive system 210: pump
212, 214, 216: Work implement 222, 224, 226: Directional switching valve
230: flow control valve 232: flow path
240: relief valve 250: tank

Claims

A direction switching valve 110 disposed between the pump 210 and the predetermined work machine 214 to control the start, stop and direction switching of the work machine by switching the spool 114 when the pilot signal pressure is applied; Parallel passage 120 for supplying hydraulic oil in the housing 112 of the directional control valve, poppet 130 formed to open and close the parallel passage 120, and when the auxiliary pilot signal pressure is applied, It includes a flow control valve 140 for controlling the opening and closing degree,
The flow control valve 140 has a main body 142 that is sealingly fastened to a portion of the housing 112 in which the poppet 130 is formed, and the main body 142 can slide vertically corresponding to the poppet 130. Piston 144 and the pilot piston 146 disposed in sequence, and the pilot port 148 for guiding the auxiliary pilot signal pressure to the upper portion of the pilot piston is formed,
An annular pressure portion 146b for pressing the pilot piston 146 toward the piston 144 is further formed in the body 142 along the circumference of the pilot piston,
The cross-sectional area A 'of the annular pressure part 146b and the cross-sectional area A of the lower part of the poppet 130 facing the parallel passage 120 are configured to be the same, and the annular pressure part 146b is formed in the housing ( 112) By connecting the parallel passage within the passage 120 and the flow path 150, the opening and closing degree of the poppet 130 is controlled regardless of the pressure of the parallel passage (100).

The method of claim 1, wherein a poppet spring 152 for elastically supporting the poppet 130 in the direction toward the parallel passage 120 is further formed in the housing 112, the pilot piston 146 to the pilot And a pilot spring (154) elastically supporting in a direction toward the port (148) is further formed in the body (142).

The cross-sectional area of the upper portion 146a of the pilot piston 146 that receives the auxiliary pilot signal pressure Pi, the cross-sectional area of the lower portion of the piston 144 a, the poppet 130 and the piston 144. When the pressure formed in the space between P _A , the pressure in the parallel passage 120, P _B , and the sum of the forces by the springs 152 and 154 are F_springs, the poppet 130 is centered. The equation of force formed by:
(aA) × P _A + F_spring = S × Pi
Variable flow control device that is.

4. The variable flow control device according to claim 3, wherein the cross-sectional area (a) of the piston (144) and the cross-sectional area (A) of the lower part of the poppet (130) facing the parallel passage (120) are configured equally.

4. The variable flow control device according to claim 3, wherein the cross-sectional area (a) of the piston (144) is configured to be larger than the cross-sectional area (A) of the lower portion of the poppet (130) facing the parallel passage (120).