JPH0320620Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a poppet valve that controls the flow rate by adjusting the amount of movement of the poppet by moving a pilot spool. This invention relates to improvements in poppet valves that can be moved by pressure.

[Conventional technology]

Figure 2 is a schematic structural diagram of a conventional poppet valve.
Main body 11 having an inlet 16 and an outlet 17
A second hole 13 and a third hole 14 perpendicular to the inlet 16 and the outlet 17 are bored in the inlet 16 . A poppet 15 is slidably inserted into the second hole 13, and the tip (lower end in the figure) of the poppet 15 has an inclined portion 18 that communicates and blocks the inlet 16 and the outlet 17. There is. The corner of the third hole 14 facing the inclined part 18 forms a seat part 19, and this inclined part 18 and the seat part 1
The flow rate of the pressure fluid flowing from the inlet 16 to the outlet 17 is controlled by the gap between the inlet 16 and the outlet 9 . The main body 1
1 has a pilot passage 4 communicating with the second hole 13.
A discharge passage 22 communicating with the tank 21 and the tank 21 is bored.

A hole 23 is bored in the center of the poppet 15, and a pilot spool 25 that passes through a lid 24 attached to the top of the main body 11 is slidably inserted into this hole 23. Since the screw 26 of the spool 25 is screwed into the lid 24, the spool 25 moves (up and down in the figure) when the handle 27 is rotated.

When the poppet 15 and the pilot spool 25 are in the state shown, that is, the inclined portion 1 of the poppet 15
8 is in contact with the seat portion 19 and the inlet 16 and outlet 17 are blocked, the hole 23 is in contact with both ends of the small diameter portion 28 provided in the pilot spool 25.
The poppet 1 communicates with a first passage 29 and a second passage 30 which are bored in the radial direction of the poppet 15.
A first groove 31 and a second groove 32 are formed on the outer circumferential surface of 5.
is formed. Note that the first groove 31 and the second groove 32 communicate with the tank 21 and the pilot passage 40 via the discharge passage 22, respectively. Further, a third flow path 34 communicating with a chamber 33 formed by the poppet 15 and the lid 24 is provided in a portion of the pilot spool 25 facing the small diameter portion 28 . 35 is an air vent hole below the hole 23 when the pilot spool 25 moves.

In such a configuration, the pilot pressure flowing into the pilot passage 40 flows through the second groove 32 and the first groove 3.
1 through the smaller diameter portion 28 and the third flow path 34 to the chamber 33
When the pressure is applied to the poppet 15 of the chamber 33, the poppet 15 is lowered in the figure, and the inclined part 18 comes into contact with the seat part 19, and the outlet 1 is moved from the inlet 16 to the outlet 1.
Pressure fluid flowing to zero is blocked from flowing. In this state, the pilot spool 25 is attached to the handle 27.
When the chamber 33 communicates with the tank 21 from the discharge passage 22 through the smaller diameter portion 28, the first passage 29, and the first groove 31 than the third passage 34, the fluid in the chamber 33 Since the water flows from the discharge passage 22 to the tank 21, the poppet 15 rises, and the poppet 15
Since the inclined portion 18 of is separated from the seat portion 19, the pressure fluid flows from the inlet 16 to the outlet 17. The distance between the inclined portion 18 of the poppet 15 and the seat portion 19 is increased by the amount of movement of the pilot spool 25, and the pressure fluid acting on the inclined portion 18 of the poppet 15 is
It is determined by the balance of the pressure fluid acting on the poppet 15 of No. 3, and the pressure fluid flowing from the inlet 16 to the outlet 17 can be maintained at a constant flow rate.

[The problem that the idea attempts to solve]

However, in a state where this constant flow rate can be maintained, fluid leaking from the gap between the poppet 15 and the main body 11 flows from the discharge passage 22 to the tank 21, causing the poppet 15 to move slightly (rising in the figure). The pressure fluid flowing through is not maintained at a constant flow rate.

Therefore, in order to maintain a constant flow rate, the inlet 16
The pilot pressure in the pilot passage 40 is always made higher than the pressure of the pressure fluid in the valve, so that even if the poppet 15 tries to move slightly due to leakage, the poppet 15 will not move slightly.
The opening degree of the main body 11 and the poppet 15 can be controlled to a certain amount by regulating the movement of the poppet 15.

In this way, in conventional poppet valves, the pilot pressure was set higher than the line pressure in order to keep the opening of the poppet valve constant, so a dedicated hydraulic circuit was required to operate the pilot pressure. This was a factor in increasing the cost of poppet valves.

Furthermore, if the pilot pressure is controlled to be higher than the line pressure, surge pressure is generated, which is a factor in worsening poppet responsiveness.

Furthermore, the cross-sectional area of the rear side of the poppet is smaller than the cross-sectional area of the high-pressure side through which liquid flows by the cross-sectional area of the pilot spool. Therefore, in order to control this poppet, it is necessary to provide an auxiliary means such as a spring on the rear side.When the poppet moves a large amount or when the hydraulic pressure is high, a spring with a strong force and a large stroke is required. This made the design of the equipment more difficult and made the equipment larger.

This invention eliminates these drawbacks,
It is an object of the present invention to provide a poppet valve capable of controlling the opening degree of pressure fluid at a constant level by controlling the amount of movement of the poppet by the line pressure acting on the poppet.

[Means to solve the problem]

The poppet valve of the present invention has first to third holes of different diameters continuously drilled on the same axis, and the first to third holes have different diameters.
and an inlet and an outlet that communicate with the second hole, respectively, a discharge passage that communicates the first hole with the tank, and a second passage that communicates the inlet and the first hole. A main body having a hole formed therein, a lid attached to the main body by fitting into a first hole of the main body, a control motor attached to the lid, and a lid slidably fitted to the lid by the control motor. a pilot spool having a small diameter portion that moves along the longitudinal direction of the first to third holes of the main body; It is inserted and detached from and contacts the seat part that is the corner between the second hole of the main body and the inlet, and connects the inlet and the outlet.
A sloped portion is provided at the junction of the large diameter portion and the small diameter portion so as to block the fluid and adjust the flow rate of the fluid flowing from the inlet to the outlet, and a first groove communicating with the discharge passage of the main body is provided on the outer periphery. A first passage communicating between the first groove and the hole into which the pilot spool is inserted is bored close to the end of the small diameter portion of the pilot spool, and a second groove communicating with the second passage is formed on the outer periphery. A second flow path communicating between the second groove and the hole into which the pilot spool is inserted is bored close to the end of the small diameter part of the pilot spool, and the small diameter part of the pilot spool is connected to the lid and main body. a poppet having a third flow path in communication with the chamber formed by the first hole, and when the pilot spool is moved by applying pressure fluid to the inclined part of the poppet and the chamber of the main body, The diameter of the large diameter part of the poppet inserted into the first and third holes is d ₃ , the diameter of the small diameter part is d ₁ , the diameter of the pilot spool is d ₂ , and the relationship d ₁ > d ₂ . It is characterized in that the flow rate of the pressurized fluid flowing from the inlet to the outlet is controlled by adjusting the gap between the inclined part of the poppet and the seat part of the main body.

[Effect]

First to third holes having different diameters are continuously drilled on the same axis, and an inlet and an outlet communicating with the first and second holes are respectively bored, and the first hole is connected to the tank. A lid is attached to a main body in which a discharge passage communicating with the inlet and a second passage communicating with the inlet and the first hole are formed, and the lid is fitted into the first hole of the main body. A pilot spool, which is slidably fitted to this lid and has a small diameter portion and moves in the longitudinal direction of the first to third holes of the main body, is fitted by a control motor attached to the lid. The large diameter part and the small diameter part are detached from and contacted with the seat part at the corner of the hole and the inlet to connect and block the inlet and the outlet, and to adjust the flow rate of the fluid flowing from the inlet to the outlet. A first groove communicating with the discharge passage is provided on the outer periphery, and a first flow passage communicating between the first groove and the hole into which the pilot spool is inserted is provided in the small diameter part of the pilot spool. A second flow path is formed adjacent to the end of the small diameter portion of the pilot spool, and a chamber consisting of the small diameter portion of the pilot spool, the lid, and the first hole of the main body is formed. A poppet with a third passage communicating with the first and third
When the pilot spool is moved by applying pressure fluid to the slope of the poppet and the chamber of the main body, the poppet inserted into the first and third holes of the main body is slidably inserted into the first and third holes of the main body. Set the diameter of the large diameter part to d ₃ and the diameter of the small diameter part to d ₁ , set the diameter of the pilot spool to d ₂ , and adjust the gap between the inclined part of the poppet and the seat part of the main body according to the relationship d ₁ > d ₂ . to control the flow rate of pressurized fluid flowing from the inlet to the outlet.

〔Example〕

Hereinafter, a detailed explanation will be given with reference to FIG. 1 showing an embodiment of the present invention. In the drawings, components having the same functions as those in FIG.

Holes 13, 14 and 20 with different diameters are coaxially bored in the main body 11.
4, a poppet 15 is slidably inserted into the poppet 15, in which the large diameter part 15a and the small diameter part 15b have diameters _d3 and _d1 , respectively, and the joining part of the large diameter part 15a and the small diameter part 15b is an inclined part 18. There is. In the illustrated state, the main body 11 has an inlet 16 for pressurized fluid perpendicular to the small diameter portion 15b of the poppet 15, and an outlet 17 perpendicular to the large diameter portion 15a.

The pilot spool 25 is slidably fitted into a hole 23 bored in the center of the poppet 15.
The upper end is connected to an output shaft 39 of a control motor 38 via a link 36 and an arm 37 pin-connected thereto. Therefore, when the control motor 38 is driven, the speed of movement of the pilot spool 25 is the lowest in the illustrated position, but the speed of movement of the pilot spool 25 is the highest when the arm 37 is in the horizontal position. A passage 35 is provided at the center of the small diameter portion 15b of the poppet 15 for communicating the hole 23 of the large diameter portion 15a with the atmosphere.

Next, the operation of the embodiment described above will be explained. In the illustrated state, pressure fluid flows into the inlet 16 and the inclined portion 18
Even if the poppet 15 tries to move (rise in the figure) due to pressure at the inlet 16 in the chamber 3,
3 is closed by the poppet 15 and the pilot spool 25,
The poppet 15 remains in this position and does not move (raise in the figure). Therefore, the slope 1 of the poppet 15
8 is in contact with the seat portion 19, so the fluid at the inlet 16 does not flow to the outlet 17. Here, when the output shaft 39 of the control motor 38 is rotated counterclockwise, the pilot spool 25 moves (raises in the figure).
The third flow path 34 extends from the small diameter portion 28 to the first flow path 2.
9, the first groove 31 and the discharge passage 22 communicate with the tank 21, so that the pressure oil in the chamber 33 can flow out into the tank 21.

Therefore, when the poppet 15 rises to a position where the second flow path 30 is cut off from the small diameter portion 28 due to the movement (rising in the figure) of the inclined portion 18 in response to the hydraulic pressure, the chamber 33
Since it is also cut off from tank 21, poppet 15
stops at this position, and the inclined part 18 and seat part 19
and are kept 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 lowered by the control motor 38 when the poppet 15 is in the above-mentioned position, that is, above the position shown, the second
The pressure fluid in the passage 20 flows from the second groove 32 through the second passage 30, the small diameter section 28 and the third passage 34 into the chamber 33 and acts on the upper surface of the poppet 15. Here, assuming that the diameter of the large diameter portion 15a of the poppet 15 is d ₃ , the diameter of the small diameter portion 15b is d ₁ , and the diameter of the pilot spool 25 is d ₂ , the cross-sectional area of the large diameter portion 15a of the poppet 15 on the chamber 33 side is ( _d32 ⁻ _d22 ⁾
, the cross-sectional area of the small diameter portion 15b is π/4(d ₃ ² −d ₂ ² ), the cross-sectional area of the small diameter portion 15b is π/4(d ₃ ² −d ₁ ² ), and d ₁ >d ₂ , the cross-sectional area of the poppet 15 is larger on the large diameter portion 15a side than on the small diameter portion 15b side, so the poppet 15 moves (downwards in the figure) due to the area difference,
The flow rate of the pressure fluid flowing from the inlet 16 to the outlet 17 is reduced. Note that when the poppet 15 is moved (downward in the figure) to a position where the second flow path 30 is cut off from the small diameter portion 28 (downward in the figure), the chamber 33
Since no pressure fluid flows into the poppet 15, the poppet 15 is stopped and the inclined portion 18 and the seat portion 19 are maintained at a constant distance. That is, even when the poppet 15 is lowered, it moves by the amount of movement of the pilot spool 25 and then stops.

Although this embodiment has been described with the poppet 15 in the vertical position, the poppet 15 is not limited to the vertical position, but may be in an inverted position, an inclined position, or the like.

[Effect of idea]

As explained above, the present invention connects the pilot spool and the control motor via a link mechanism, and when adjusting the opening between the main body seat and the poppet slope, the pressure receiving area on the poppet seat side is In order to increase the pressure receiving area on the pilot spool side of the poppet, the diameter of the small diameter part of the poppet is made larger than the diameter of the pilot spool, so that the poppet always moves toward the seat side, so leakage between the poppet and the main body is prevented. Even if the poppet tries to move slightly, the degree of opening between the seat portion of the main body and the inclined portion of the poppet remains constant, so a constant flow rate is maintained.

Furthermore, since the poppet is opened and closed by line pressure, auxiliary means such as springs are not required, making it possible to reduce the overall size and cost.

Furthermore, since the pilot spool that controls the movement of the poppet is connected to the control motor via a link mechanism, the movement speed of the pilot spool becomes almost a sine curve, so the movement speed is fast at the initial stage of opening, and the movement speed at the end when the opening reaches the maximum. The speed becomes faster and an ideal opening operation can be obtained.

Therefore, when used in a hydraulic circuit that sets the injection conditions of a die-casting machine, etc., the injection conditions can be reliably held constant, making it possible to mold products under constant injection conditions, which contributes to the yield of molded products. It is important to do so.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a poppet valve showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional poppet valve. 11... Main body, 12-14... Hole, 15... Poppet, 16... Inlet, 17... Outlet, 18
... Sloped part, 19 ... Seat part, 20 ... Passage,
21...tank, 22...discharge passage, 23...
Hole, 24... Lid, 25... Pilot spool, 26... Screw, 27... Handle, 28...
Small diameter portion, 29, 30... flow path, 31, 31...
Groove, 33... Chamber, 34... Channel, 35... Hole, 3
6... Link, 37... Arm, 38... Control motor, 39... Output shaft, 40... Pilot passage.

Claims (1)

[Scope of utility model registration request] First to third holes having different diameters are continuously drilled on the same axis, an inlet and an outlet communicating with the first and second holes are respectively bored, and the first hole is connected to the tank. a main body having a discharge passage communicating with the main body, and a second passage communicating the inflow port with the first hole; a control motor attached to the lid; a pilot spool that moves along with the main body; Slanted at the joint portion of the large diameter portion and the small diameter portion so as to separate from and contact the seat portion to communicate/block the inflow port and the outflow port, and adjust the flow rate of the fluid flowing from the inflow port to the outflow port. A first groove communicating with the discharge passage is provided on the outer periphery, and a first flow path communicating between the first groove and the hole into which the pilot spool is inserted is provided at the end of the small diameter portion of the pilot spool. drilled in close proximity to
a second groove communicating with the second passage is provided on the outer periphery;
A second channel communicating between the second groove and the hole into which the pilot spool is inserted is bored close to the end of the small diameter part of the pilot spool, and the small diameter part of the pilot spool and the lid and a poppet having a third flow path in communication with the chamber formed by the first hole of the main body, and the pilot spool is moved by applying pressure fluid to the inclined part of the poppet and the chamber of the main body. Then, the diameter of the large diameter part of the poppet inserted into the first and third holes of the main body is d ₃ and the diameter of the small diameter part is d ₁
The diameter of the pilot spool is set to _d2 , and the gap between _the inclined part of the poppet and the seat part _of the main body is adjusted so that the pressure fluid flows from the inlet to the outlet. A poppet valve characterized by controlling the flow rate of.