JP2526615Y2 - Air driven pump - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention relates to an air-driven pump that is most suitable for use in hydraulic jacks and the like.

[Conventional technology and its problems]

Various air-driven pumps used for hydraulic jacks and the like have been conventionally proposed, and the present applicant has previously developed an air-driven pump as shown in FIG. 3 (Japanese Patent Application No. 1-32181). .

As shown in FIG. 3, this air-driven pump is provided with a valve housing b at an end of a cylinder tube a,
A piston c is slidably inserted into the cylinder tube a to partition a compressed air chamber d within the cylinder tube a with the piston c, and a plunger l for generating hydraulic pressure is provided at one end of the piston c. At the end, a plunger e for pilot pressure control is provided in series with the plunger l for hydraulic pressure generation.
A return spring f is provided at one end of the piston c so as to face the compressed air chamber d. A poppet type exhaust valve h for opening and closing the compressed air chamber d to an exhaust passage g is provided in the valve housing b in addition to the piston c. An air supply valve j for opening and closing the pressure chamber d to the intake hole i is provided in the valve housing b so as to face the other end of the piston.

In this air-driven pump, when the exhaust valve h is closed and the air supply valve j is open, when the compressed air is supplied from the intake port i to the compressed air chamber d, the piston c moves to the left and the pressure oil is discharged by the pressure-side hydraulic pressure generating plunger. Let it. When the piston c moves leftward to a certain position, the pressure oil in the compressed air chamber d is supplied to the pilot chamber k as the pilot pressure via the pilot pressure control plunger e, and the pilot pressure closes the air supply valve j and the exhaust valve h.
Opens. Therefore, the compressed air chamber d opens into the exhaust passage g, and the piston c is returned to the right by the return spring f.
The air supply valve j and the exhaust valve h are pushed in at the right end face of, and the air supply valve j is opened and the exhaust valve h is closed. However, since the air supply valve j is a poppet type valve, in the case of processing in which the exhaust valve h is slightly opened, the compressed air flows from the intake port i to the compressed air chamber d, and the pressures P ₁ and P _{2 on} both sides of the valve body are reduced. The pressure difference (P ₁ > P ₂ ) may cause the air supply valve j to close and the piston c not to return to the original position. Therefore, as shown in the figure, when the opening stroke of the air supply valve j is increased by lengthening the end of the air supply valve j, the air supply valve j opens greatly before the exhaust valve h is completely closed, and flows out from the intake hole i. The pressurized air may escape from the exhaust valve h to the exhaust passage g, and may cause malfunction of the piston c due to pressure loss. Therefore, in order to eliminate the above-mentioned problems, high processing accuracy is required, and workability becomes difficult.

Therefore, the present invention has been made in view of the above-described circumstances, and an object thereof is to ensure an appropriate connection between a so-called air supply valve opening / closing operation and a so-called exhaust valve opening / closing operation. Another object of the present invention is to provide an air-driven pump capable of fully performing a predetermined operation of the air-driven pump.

[Means for solving the problem]

In order to achieve the above object, the configuration of the present invention is to provide a valve housing at the end of a cylinder tube, slidably insert a piston into the cylinder tube, and partition the compressed air chamber in the cylinder tube with the piston. A plunger for generating hydraulic pressure is provided at one end of the piston, a plunger for controlling pilot pressure is provided in series with the plunger for generating hydraulic pressure at the other end of the piston, and a return spring facing the compressed air chamber is provided at one end of the piston. A poppet-type exhaust valve for opening and closing the compressed air chamber to the exhaust passage is provided in the valve housing opposite to the other end of the piston, and the valve housing is also opened and closed to the intake hole in the valve housing. An air-driven pump having an air supply valve opposed to the other end of the piston, wherein the air supply valve has a sleeve provided in a valve housing. A spool-type valve body movably inserted into the sleeve, the sleeve having a radial communication hole communicating with the intake hole, and the valve body having a radial direction in which the communication hole is opened and closed. And a vertical hole in the axial direction that opens into the compressed air chamber.

[Action]

The piston in the cylinder tube reciprocates by the pressure and pressure supplied to the compressed air chamber in the cylinder tube and the urging force of the return spring to drive the plunger for generating hydraulic pressure.

Then, the supply of the compressed air to the compressed air chamber is performed through the supply valve which is in an open state when the exhaust valve is closed.
The piston moves overcoming the urging force of the return spring.

When the piston reaches the forward end of its stroke area, the pressure and pressure of the compressed air chamber are introduced into each pilot chamber in the exhaust valve and the air supply valve, and the exhaust valve and the air supply valve are switched. .

That is, while the exhaust valve is open, the air supply valve is closed.

As a result, the compressed air in the compressed air chamber is released to the atmosphere through the exhaust valve, and the supply of the compressed air to the compressed air chamber is stopped by closing the air supply valve.

As a result, the hydraulic pressure generating plunger that operates integrally with the reciprocating piston performs suction and discharge of the hydraulic oil by the reciprocating motion.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment.

As shown in FIG. 1, in an air-driven pump according to an embodiment of the present invention, a piston 2 is slidably housed in a cylinder tube 1.

Then, the piston 2 is held so as to protrude to the other end side on the right side in the figure, and the plunger 3 for pilot pressure control is held.
And a hydraulic pressure generating plunger 4 protrudingly provided at one end side on the left side in the figure, and a pilot pressure controlling plunger 3 and a hydraulic pressure generating plunger. 4 are set in series with the piston 2 sandwiched therebetween.

The plunger 4 for generating hydraulic pressure has its base end, which is the right end in the figure, held by the plate 5, and its distal end, which is the left end in the figure, is inserted through the pump housing 6 so as to be freely retractable. 2 are set to move together when sliding.

Also, the hydraulic pressure generating plunger 4 is provided with a cylinder cap 7 and a plate 5 for connecting the pump housing 6 and closing one end of the cylinder tube 1 at the left end in the drawing.
The piston 2 is pressed against the other side of the piston 2 on the left side in FIG.

Although not shown, the inside of the pump housing 6 communicates with a suction port and a discharge port of hydraulic oil provided in the cylinder cap 7 via a suction valve and a discharge valve, respectively. The hydraulic fluid is formed so as to be discharged from the discharge port as high-pressure oil from the suction port when it comes and goes in the housing 6.

On the other hand, the pilot pressure control plunger 3 is formed of a cylindrical body, and has a right end in the figure, a tip of which closes the other end of the cylinder tube 1 which is a right end in the figure. Central hole 10a drilled in the shaft core
It will be guided to.

Another hole 10 is provided in the shaft core on the outer end face of the valve housing 10.
b is opened, and the base end of the guide rod 11 is housed in the hole 10b.

The tip of the guide rod 11 is inserted into the shaft center of the plunger 3 for pilot pressure control.

The insertion state of the guide rod 11 into the pilot pressure control plunger 3 is such that the distal end side of the pilot pressure control plunger 3 is in close sliding contact with the guide rod 11 while the guide rod 11 is at the base end side of the pilot pressure control plunger 3. An annular gap passage 3a is formed between the outer circumference of the groove 11 and the outer periphery of the groove 11a.

The annular gap passage 3a is set so as to communicate with a pilot pressure introduction passage 11a that is opened inside the guide rod 11.

The annular gap passage 3a is assumed to communicate with an open chamber A formed in the cylinder tube 1 on the left side of the piston 2 in the drawing through a communication hole 9a formed in the spacer 9 and a communication hole 5a formed in the plate 5. The open chamber A is open to the outside of the cylinder tube 1 through a communication hole (not shown) formed in a side wall of the cylinder tube 1 outside the piston stroke area.

The central hole 10a communicates with a pressure chamber B formed in the cylinder tube 1 on the right side of the piston 2 in the drawing.

Therefore, when the piston 2 slides in the cylinder tube 1 and strokes to the left in the drawing, and the guide rod 11 comes out of the pilot pressure control plunger 3, the vicinity of immediately after the start of the stroke of the piston 2 The pilot pressure introduction passage 11a opened in the guide rod 11 communicates with the annular gap passage 3a, but almost immediately after the stroke of the piston 2 advances, the pilot pressure introduction passage 11a and the annular gap passage 3a are opened.
Communication with a will be cut off.

When the stroke of the piston 2 further advances, the central hole 10a formed in the valve housing 10 communicates with the pilot pressure introduction path 11a.

On the other hand, the valve housing 10 has an air supply valve 12 and an exhaust valve 13 arranged in parallel with and sandwiching the central hole 10a.

The exhaust valve 12 is provided to supply compressed air to the compressed air chamber B. In this embodiment, the exhaust valve 12 is slidable in the sleeve 12b disposed in the valve housing 10 and the sleeve 12b. And a spool-type valve body 12a housed in the valve body.

The valve body 12a has its tip, which is the left end in the drawing, located in the piston stroke region of the compressed air chamber B,
The other end, which is the right end in the figure, is present in the pilot chamber 12c, and the other end is set as a pressure receiving surface that receives pilot pressure.

One end of the sleeve 12b is locked by a snap ring 12d interposed in the valve housing 10, and the other end is locked by a plug 12e fitted in the valve housing 10. Is fixed at a predetermined position.

The pilot chamber 12c is provided with a through hole 12 formed in the plug 12e.
It communicates with the pilot pressure introduction passage 11a in the guide rod 11 through a through hole 10c formed in the valve housing f and the valve housing 10.

It is assumed that the sleeve 12 has a communication hole 12g that penetrates the radius and communicates the outer peripheral side and the inner peripheral side.

The communication hole 12g communicates with an intake hole 10d formed in the valve housing 10 on the one hand, and is selectively opened and closed by a horizontal hole 12h formed in the valve body 12a on the other hand. That is, the valve body 12a communicates when the valve body 12a tends to retreat in the sleeve 12b, and closes when the valve body 12a reverses.

The communication hole 12g is formed along the axial direction in the valve body 12a through the horizontal hole 12h, and is open to the compressed air chamber B.
communicates with i.

Therefore, in the air supply valve 12 according to this embodiment, when the pilot pressure in the pilot chamber 12c is not supplied, the valve body 12a is in the retracted state in the sleeve 12b, and the communication hole of the sleeve 12b is formed. 12g communicates with the horizontal hole 12h of the valve body 12a to allow the compressed air from the intake hole 10d to flow into the compressed air chamber B formed in the cylinder tube 1 via the air supply valve 12. .

When a predetermined pilot pressure is supplied into the pilot chamber 12c, the valve body 12a tends to move forward in the sleeve 12b, and the communication hole 12g of the sleeve 12b and the horizontal hole 12h of the valve body 12a.
With the air supply valve 12 of the compressed air from the intake port 10d.
To the air pressure chamber B through the air passage.

Further, since the air supply valve 12 according to this embodiment is configured such that the valve main body 12a is formed of a spool valve that slides in the sleeve 12b, compared with the case where the valve main body 12a is formed of a poppet valve as in the above-described conventional example. Thus, there is no fear of malfunction of the valve body 12a due to the generation of a differential pressure before and after the valve body 12a, and reliable control of the valve body 12a, that is, reliable opening and closing control of the air supply valve 12 can be performed.

And since the air supply valve 12 according to this embodiment is composed of the sleeve 12b and the spool-type valve body 12a that slides inside the sleeve 12b, the valve opening degree of the air supply valve 12, that is,
The opening degree of the lateral hole 12h formed in the valve body 12a can be set small, and therefore, in terms of comparison, the exhaust valve
It is possible to set the valve opening of the thirteenth large.

Next, the exhaust valve 13 is provided for discharging the compressed air from the compressed air chamber B to the outside through the exhaust passage 10e opened in the valve housing 10, and in this embodiment, A seat member 13b held at the tip of a valve body 13a formed in a poppet valve mode is formed so as to shut off the exhaust passage 10e when the valve body 13a retreats.

The exhaust valve 13 has its left end, which is the left end in the drawing, of the valve body 13a in the piston stroke region of the compressed air chamber B, while the other end, which is the right end in the drawing, is connected to the pilot chamber 13a.
The other end surface is set as a pressure receiving surface for receiving pilot pressure.

The pilot chamber 13c is defined by a plug 13d fitted in the valve housing 10, and communicates with a pilot pressure introduction passage 11a in the guide rod 11 through a through hole 10f formed in the valve housing 10. ing.

Therefore, in the exhaust valve 13 according to this embodiment, when the pilot pressure is not supplied into the pilot chamber 13c, the valve body 13a is in the retreat state in the exhaust passage 10e,
The exhaust passage 10e is blocked by the seat member 13b at the distal end of the valve body 13a, and the flow of compressed air from the compressed air chamber B to the outside through the exhaust passage 10e is prevented.

When a predetermined pilot pressure is supplied into the pilot chamber 13c, the valve body 13a tends to move forward in the exhaust passage 10e, so that the blockage of the exhaust passage 10e by the seat member 13b is released. The communication between the exhaust passage 10e and the compressed air chamber B is allowed, and the compressed air from the compressed air chamber B flows out.

Therefore, according to the air-driven pump according to this embodiment formed as described above, when the left end face of the piston 2 in the drawing is at the stroke end of the backward stroke at the point S in the drawing, the air supply valve is provided. The respective ends of the valve bodies 12a and 13a of the exhaust valve 12 and the exhaust valve 13 are pushed by the right end face of the piston 2 in the drawing, and are in the illustrated state. At this time, while the supply valve 12 is in the open state, As a result, the exhaust valve 13 is in an open state.

The above state is the bottom dead center position in FIG.

Then, the compressed air sent from the intake hole 10d
When the air flows into the compressed air chamber B through the passage, the piston 2 receiving the chamber pressure in the compressed air chamber B overcomes the urging force of the return spring 8 and moves leftward in the drawing.

The plunger 3 for pilot pressure control and the plunger 4 for generating hydraulic pressure move in the same direction in communication with the movement of the piston 2, and at this time, the hydraulic oil from inside the pump housing 6 moves to the outside due to the advance of the plunger 4 for generating hydraulic pressure. It will be ejected.

On the other hand, at the same time, the movement of the plunger 3 for pilot pressure control causes the sliding portion at the tip of the plunger 3 to close the opening of the pilot pressure introduction passage 11a of the guide rod 11, and the communication holes 5a, 5a, The communicating hole 9a of the spacer 9, the annular gap passage 3a, the pilot pressure introducing passage 11a, and the through holes 10c and 10f.
Opening room A and each pilot room 12c realized through
Communication with 13c will be interrupted.

As the pilot pressure control plunger 3 further advances (piston movement), the sliding contact portion of the pilot pressure control plunger 3 passes through the opening of the pilot pressure introduction passage 11a. Road
11a will open directly into the central hole 10a of the valve housing 10.

Accordingly, the chamber pressure of the compressed air chamber B communicated by the gap between the central hole 10a and the pilot pressure control plunger 3 is supplied as pilot pressure to the pilot chambers 12c and 13c.

The supply of the pilot pressure to each of the pilot chambers 12c and 13c causes each of the valve bodies 12a and 13a to move leftward in the drawing and switch.

That is, the supply valve 12 is closed and the supply of compressed air to the compressed air chamber B is stopped, and the exhaust valve 13 is opened to release the compressed air in the compressed air chamber B to the outside through the exhaust passage 10e. Will be allowed.

The stroke end position of the forward stroke of the piston 2 at this time is indicated by a point F in the drawing.

As described above, the piston 2 after the chamber pressure in the pneumatic chamber B is released is moved rightward in the drawing by the urging force of the return spring 9.

In this return stroke, the hydraulic pressure generating plunger 4 moves in a direction to come out of the inside of the pump housing 6, and the pump housing 6 can be operated again.

On the other hand, at the beginning of the return operation, the pilot pressure control plunger 3
Is switched from the central hole 10a to the annular gap passage 3a, and the pilot chambers 12c and 13c are communicated with the open chamber A to release the respective pilot pressures.

Then, with the further return of the piston 2, each valve body 12a of the air supply valve 12 and the exhaust valve 13 protruding toward the air chamber B,
The end face of piston 2 pushes back the tip of 13a,
The supply valve 12 and the exhaust valve 13 return to the initial state described at the beginning.

Thereafter, by repeating the above-described operations, the pressurizing pump operation by the hydraulic pressure generating plunger 4 is continuously performed.

The opening / closing operation of the air supply valve 12 and the exhaust valve 13 and the opening / closing operation of the pilot pressure control plunger 3 are as shown in FIG.

[Effect of the invention]

 As described above, according to the present invention, the following effects can be obtained.

When the pump operation is realized by the operation of the piston reciprocating by the compressed air supplied to the compressed air chamber and the urging force of the return spring, the supply air valve is closed during the return operation of the piston to supply the compressed air to the compressed air chamber. Since the valve can be stopped and the exhaust valve is opened, reliable operation of the air-driven pump can be expected, and the compressed air from the compressed air chamber is discharged to the outside without involvement of large flow path resistance. Therefore, even if the urging force of the return spring is weakened, it is possible to reduce the consumption of the compressed air.

The air supply valve is composed of a sleeve and a spool-type valve body movably inserted into the sleeve, and the opening and closing of the intake port and the pneumatic chamber are formed in the sleeve and the valve body, and controlled by the communication hole and the lateral hole. Therefore, even when the opening degree of the exhaust valve is small, the valve body does not close due to the differential pressure. Moreover, when the air supply valve is fully opened due to the processing accuracy of the communication hole and the horizontal hole, it is possible to control the exhaust valve to be fully open, and it is possible to accurately control the opening and closing operation of the air supply valve and the opening and closing operation of the exhaust valve. The connection is secured, and the predetermined operation of the air-driven pump itself can be fully exhibited.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing a pneumatic driven pump according to an embodiment of the present invention, FIG. 2 is a diagram showing each valve opening together with a piston stroke, and FIG. 3 is a partial cutaway of a conventional air driven pump. It is a chipping sectional view. [Description of Signs] 1 ... Cylinder tube 2 ... Piston 3 ... Plunger for pilot pressure control 4 ... Plunger for hydraulic pressure generation 8 ... Return spring 10 ... Valve housing 10d ... Intake hole 12 ... Supply valve 12a, 13a ... Valve body 12b ... Sleeve 12c, 13c ... Pilot chamber 12g ... Communication hole 12h ... Horizontal hole 12i ... Vertical hole 13 ... Exhaust valve B ... Pressure chamber

Claims (1)

(57) [Scope of request for utility model registration] A valve housing is provided at an end of a cylinder tube, a piston is slidably inserted into the cylinder tube, and a pressure chamber is defined in the cylinder tube by the piston. A plunger for pilot pressure control is provided in series with a plunger for generating hydraulic pressure at the other end of the piston, and a return spring facing the air chamber is provided at one end of the piston. Is provided at the other end of the piston with a poppet type exhaust valve for opening and closing the compressed air chamber to the exhaust passage, and an air supply valve for opening and closing the compressed air chamber to the intake hole is also provided at the other end of the piston in the valve housing. In the air-driven pump provided opposite to the air-driven pump, the air supply valve is movably inserted into the sleeve provided in the valve housing and the sleeve. The sleeve is provided with a radial communication hole communicating with the intake hole, and the valve body is opened to a radial lateral hole opened and closed by the communication hole and a pressure chamber. An air-driven pump having an axial vertical hole.