JPH0326370Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field to which the invention belongs] The present invention relates to a digital flow directional control valve.

[Prior art]

In a conventional digital flow rate directional control valve, for example, the pressure at both ends of the spool is adjusted by a nozzle flapper valve, and the position of the nozzle flapper valve is digitally controlled by a pulse motor to position the spool. In this method, when stopping the actuator, the nozzle flapper valve is first returned to the neutral position, and then the spool is returned to the intermediate position.
Since the spool starts moving from the neutral position during the next operation, it takes a considerable amount of time for the large flow of hydraulic fluid to reach a predetermined flow rate. Furthermore, even when reversing the direction of flow, it takes a lot of time to pass through the neutral position once, making agile operation impossible.

[Purpose of invention]

The present invention eliminates such drawbacks, and its purpose is to control the digital flow valve to a position where a predetermined flow rate is obtained in advance when the actuator is stopped, that is, when the hydraulic fluid is not flowing. When moving the actuator, a logic valve is opened to allow a large flow of hydraulic fluid to flow in an extremely short period of time, and when the flow direction is reversed, the logic valve that is already open is switched to reverse the flow in a short period of time. The purpose of the present invention is to provide a digital flow directional control valve.

[Key points of the idea]

The digital flow rate directional control valve of the present invention moves the pilot spool and makes the poppet follow the pilot spool to adjust the flow rate.The outlet of the digital flow control valve is connected to the head side and rod side of the actuator, respectively. The inlets of logic valves A and B are connected to the inlets of logic valves A and B, and the inlets of logic valves C and D, whose outlets are connected to the tank, are connected to the outlets of logic valves A and B. The flow rate of the digital flow direction switching valve is controlled by switching the pilot pressure of the logic valve to pressure oil or tank.

[Example of idea]

The present invention will be explained below with reference to FIG. 1 showing one embodiment. First, the digital flow control valve 10 will be explained. The main body 11 has three stages of holes 12 to 14 that increase in size from the left side in the figure, and the holes 13 and 14 have two stages of poppets with a left diameter of d ₁ and a right diameter of d ₂ . 15 is slidably inserted. In the state shown, the pressure fluid inlet 16 is located opposite the d ₁ diameter portion of the poppet 15.
is formed, and the tip or hole 12 of the poppet 15 is bent at right angles to form an outlet 17. Hole 12 facing the inclined portion 18 provided on the left side of the poppet 15
The corners of the tube are formed into sheets 19, and the inclined portions 18 and the sheets 19 control the flow rate of the fluid.

The main body 11 has an inlet 1 approximately in the middle of the middle hole 13.
A passage 20 that communicates between the holes 14 and the tank 21 and a passage 22 that communicates the holes 14 and the tank 21 are provided. Poppet 1
5 has one hole 23 in the center, and this hole 2
3, a pilot spool 25 is slidably inserted through a lid 24 attached to the right side of the main body 11. The right end of the pilot spool 25 is connected to the pulse motor 3 via a link 26 and an arm 27.
6, and a narrow diameter portion 28 is formed in the middle. When the poppet 15 and the pilot spool 25 are in the illustrated state, they are in contact with the top and bottom of the narrow diameter portion 28, and the hole 23
passages 29 and 3 leading to the outer periphery of poppet 15
0, and grooves 31 and 32 are formed on the outer peripheral sides of the passages 29 and 30.

Further, a passage 34 communicating with a chamber 33 formed by the upper surface of the poppet 15 and the lower surface of the lid 24 is provided in a portion of the pilot spool 25 facing the narrow diameter portion 28. Furthermore, the diameter of the pilot spool 25 is
If d ₃ , π/4(d ² ₂ −d ² ₃ )>π/4d ² ₁ , and 35 is a hole for air below the hole 23 when the pilot spool 25 moves.

In the present invention, the flow direction of the digital flow control valve 10 relative to the actuator 41 is controlled by a directional control valve mechanism 42. The same organization 4
2 consists of four logic valves 43 to 46 and an electromagnetic switching valve 47. A logic valve 43 and B
Logic valve 44 has inlets 43a and 44a connected to outlet 17 of digital flow control valve 10, and outlets 43b and 44b connected to the head and rod sides of actuator 41, respectively.
The inlets of the C logic valve 45 and the D logic valve 46 are connected to the head side and rod side of the actuator 41, respectively, and the outlets are connected to the tank 21. The A port of the electromagnetic switching valve 47 is the A logic valve 4.
3 and D logic valve 46 pilots 43C and 46
The C and B ports are connected to the pilots of the B logic valve 44 and the C logic valve 45, the P port is connected to the discharge port of the pump 48, and the T port is connected to the tank 21.

Next, the operation of the embodiment described above will be explained. In the state shown in FIG. 1, the digital flow control valve 10 has pressure fluid flowing into the inlet 16, and even if the right side of the inclined portion 18 receives pressure and the poppet 15 tries to move to the right, the passage 34 leading to the chamber 33 is closed to the poppet 15. Since it is closed by the pilot spool 25, the poppet 15
stays in this position and does not move to the right. Therefore, since the inclined portion 18 of the poppet 15 is in contact with the seat 19, the fluid at the inlet 16 does not flow out to the outlet 17. Here, when the pilot spool 25 is moved to the right by the pulse motor 36, the passage 34 passes from the narrow diameter portion 28 through the passage 30 groove 32 and then the passage 22 to the tank 2.
1, the oil in the chamber 33 can flow out into the tank 21. Therefore, the poppet 15 has an inclined portion 18
receives the hydraulic pressure and moves to the right, the inclined portion 18 separates from the seat 19, and the fluid at the inlet 16 reaches the outlet 17.

Note that when the poppet 15 moves to the right until the passage 30 is cut off from the small diameter part 28, the chamber 33 is also cut off from the tank 21, so the poppet 15 stops at this position and connects the inclined part 18 and the seat 19. Keep it at regular intervals. That is, the poppet 15 moves by the amount of movement of the pilot spool 25 and then stops.

When the pilot spool 25 is moved to the left when the poppet 15 is in the above-mentioned position, that is, to the right of the position shown in the first figure, the pressure fluid in the passage 20 flows from the groove 31 through the small diameter portion 28 of the passage 29 and through the passage 34. It flows into chamber 33 and applies pressure to the right side of poppet 15. Here, since π/4(d ² ₂ - d ² ₃ )>π/4d ² ₁ , the poppet 15 moves to the left and connects the inclined part 18 and the seat 1.
9 to reduce the flow rate.

Note that when the poppet 15 moves leftward to a position where the passage 29 is cut off from the small diameter portion 28, the poppet 15 stops because no pressure fluid flows into the chamber 33, and the inclined portion 18 and the seat 19 are kept at a constant distance. That is, the poppet 15 moves by the amount of movement of the pilot spool 25, which is moved by the digitally controlled pulse motor 36, and then stops in either case of rightward or leftward movement.

As described above, when the poppet 15 moves to the right and the solenoid switching valve 47 is switched to the left ventricle with the inlet 16 and the outlet 17 communicating with each other, the A logic valve 43 and the D logic valve 46 are activated by the pilots 43C and 46C. They are closed by receiving pressure oil from pump 48, while B logic valve 44 and C logic valve 45 are opened by the pilot opening to tank 21. Therefore, the pressure oil at the outlet 17 of the digital flow control valve 10 flows into the rod side of the actuator 41 through the B logic valve 44, and the oil at the head side flows through the C logic valve 45 into the tank 21.
Return to

In this state, the piston 4 of the actuator 41
When the electromagnetic switching valve 47 is switched to the right ventricle while 1A is moving leftward, the B logic valve 44 and C logic valve 45 are closed, and the A logic valve 43 and D logic valve 46 are opened. Therefore, the pressure oil at the outlet 17 flows into the head side of the actuator 41 through the A logic valve 43, and the oil on the rod side flows into the D logic valve 46.
Return to tank 21. Therefore, actuator 4
The flow of pressure oil to No. 1 is the reverse of the above.

FIG. 2 shows another embodiment of the digital flow control valve, and since the directional control valve mechanism 42 is completely the same as that in FIG. 1, only the digital flow control valve 51 will be described.

A poppet 55 integrally molded or attached with a nose 54 facing toward the tip is slidably inserted into the hole 53 of the main body 52, and the inclined portion 56 of the poppet 55 is inserted into the hole 53 of the main body 52.
In the position shown opposite the second seat 57, the pressure fluid inlet 58 is closed to the outlet 59.

A pilot spool 61 is slidably inserted into a concentric hole 60 in the center of the poppet 55, and the left end of the pilot spool 61 in the figure is connected to this with a pin or connected to the tank 26 via an arm 27 that is also connected with a pin. and is connected to a pulse motor 36.

A lid 62 is attached to the left end of the main body 52, and a chamber 63 is formed by the lid 62 and the left end of the poppet 55. A passage 64 leading to the inlet 58 is bent on the left side and opens in the middle of the hole 53, and a passage 65 communicating the hole 53 with the tank 21 is located to the left of the bent part of the passage 64. Two grooves 66 and 67 are provided on the outer periphery of the poppet 55.
7 communicates with the hole 60 through passages 68 and 69;
Passages 68 and 69 open into bore 60 at a location abutting small diameter portion 70 of pilot spool 61 when it is in the position shown. Passages 68 and 69
In a part that is in the middle of and has a different phase from the passage 68 etc.,
A passage 71 from the inner periphery of the poppet 55 is provided, and the passage 71 communicates with the left side of the poppet 55, or into the chamber 63, by bending. Poppet 55 Nose 5
A passage 72 for communicating the hole 60 with the atmosphere is provided at the center of the nose 54, and the outer diameter _d1 of the nose 54 is larger than the outer diameter _d2 of the pilot spool 61.

The operation of the other embodiments described above will be explained.

In the illustrated state, even if pressure fluid acts on the inlet 58, the passage 71 communicating with the chamber 63 is closed by the main body 52 and the pilot spool 61, so the poppet 55 remains in this position and does not move to the left. Therefore, since the sloped portion 56 of the poppet 55 is in contact with the seat 57, the fluid at the inlet 58 does not flow out to the outlet 59. Here, when the pulse motor 36 is rotated counterclockwise by a fixed angle, the pilot spool 61 moves to the left, and the small diameter portion 70 of the pilot spool 61 moves to the left.
Since the chamber 63 is in contact with the passage 69 communicating with the tank 21, the chamber 63 also communicates with the tank 21. As a result, the poppet 55 is pushed by the pressure fluid at the inlet 58 and moves to the left, causing the inclined portion 56 to separate from the seat 57 and the pressure fluid at the inlet 58 to communicate with the outlet 59.

Note that when the poppet 55 moves left to the position where the passage 69 is cut off from the small diameter part 70 of the pilot spool 61, the chamber 63 is also cut off from the tank 21, so the poppet 55 stops at this position and the inclined part 5
6 and the sheet 57 are kept at a constant interval. That is, the poppet 55 moves by the amount of movement of the pilot spool 61 and then stops.

When the pilot spool 61 is moved a certain distance to the right by the pulse motor 23 when the poppet 55 is to the left of the position shown, the pressure fluid in the passage 64 passes through the passage 68, the small diameter portion 70, and the passage 71 to the chamber 63.
flows into.

Here, if the outer diameter of the poppet 55 is d3, then the chamber 6
The cross-sectional area of the poppet 55 on the third side is π/4 (d ² ₃ - ^{d 2} ₂ ), the cross-sectional area of the poppet 55 on the inlet side is π/4 (d ² ₃ - d ² ₁ ), and d Since ₁ > d ₂ , the cross-sectional area of the poppet 55 is larger on the chamber 63 side. Therefore, the poppet 55 moves to the right and narrows the gap between the inclined portion 56 and the seat 57. Note that when the poppet 55 moves rightward to a position where the passage 68 is cut off from the small diameter portion 70, the poppet 55 stops because no pressure fluid flows into the chamber 63, and the inclined portion 56 and the seat 57 are kept at a constant distance. That is, the poppet 55 moves by the amount of movement of the pilot spool 61 and then stops.

As described above, when the poppet 55 moves to the left and the solenoid switching valve 47 is switched to the left ventricle with the inlet 58 and the outlet 59 communicating, the A logic valve 43 and the D logic valve 46 are activated by the pilots 43C and 46C. They are closed by receiving pressure oil from pump 48, while B logic valve 44 and C logic valve 45 are opened by the pilot opening to tank 21. Therefore, the pressure oil at the outlet 59 of the digital flow control valve 51 flows into the rod side of the actuator 41 through the B logic valve 44, and the oil at the head side flows through the C logic valve 45 into the tank 21.
Return to

In this state, the piston 4 of the actuator 41
When the electromagnetic switching valve 47 is switched to the right ventricle while 1A is moving leftward, the B logic valve 44 and C logic valve 45 are closed, and the A logic valve 43 and D logic valve 46 are opened. Therefore, the pressure oil at the outlet 59 flows into the head side of the actuator 41 through the A logic valve 43, and the oil on the rod side flows into the D logic valve 46.
Return to tank 21.

Therefore, the flow of pressure oil to the actuator 41 is reversed to the above.

[Effect of idea]

As explained above, the digital flow rate directional control valve of the present invention is composed of one digital flow rate control valve, four logic valves, and one electromagnetic switching valve for opening and closing the logic valve.

Because of this configuration, it is possible to adjust the flow rate of the digital flow control valve not only when the hydraulic fluid is flowing, but also when the hydraulic fluid is not flowing, and when the actuator is operating, the digital flow control valve can be set to a predetermined flow rate in advance. By making the adjustment and then opening the two logic valves and closing the two logic valves, it is possible to flow a predetermined flow rate to the actuator in an extremely short time compared to the conventional spool valve movement method. In this case, the larger the flow rate, the greater the effect. Furthermore, when reversing the flow direction, the above-mentioned 2.
The practical effects are great, such as the short time it takes to close one open logic valve and open two closed logic valves.

[Brief explanation of drawings]

FIG. 1 is a partially sectional system diagram of one embodiment of the present invention, and FIG. 2 is a partially sectional system diagram of another embodiment of the present invention. 10, 51...Digital flow control valve, 21...
Tank, 41...actuator, 43...A logic valve, 44...B logic valve, 45...C logic valve, 46...D logic valve.

Claims (1)

[Scope of utility model registration request] A digital flow control valve moves the pilot spool and causes the poppet to follow the pilot spool by means of pressure oil acting on the head side and seal side of the poppet to adjust the flow rate of the pressure oil flowing from the inlet to the outlet; A logic valve whose inlet is connected to the outlet of the digital flow control valve and whose outlet is connected to the head side of the actuator; and B whose inlet is connected to the outlet of the digital flow control valve and whose outlet is connected to the rod side of the actuator. a C logic valve having an inlet connected to the head side of the actuator and an outlet connected to a tank; a D logic valve having an inlet connected to the rod side of the actuator and an outlet connected to the tank; A digital flow rate directional control valve consisting of an electromagnetic switching valve that switches the connection between the pilot of the A to D logic valves to pressure oil or the tank.