JPH06185667A - Pilot operated pressure control valve - Google Patents

Abstract

PURPOSE:To enable pressure control for high pressure fluid in a device in which the pressure of fluid in a main circuit is controlled by means of a pressure control valve in response to pilot fluid from a pilot valve, by setting the pressure receiving area of a pilot fluid pressure receiving surface of a valve element in the pressure control valve, to a value which is K times as large as the pressure receiving area of a main circuit fluid receiving surface thereof. CONSTITUTION:A relief valve 14 as a module type pressure control valve composed of a valve element 15, a valve cylinder 16 and the like is incorporated in the connection part between first and second housings 1, 2. A proportional solenoid pilot valve 30 which controls pressure that does not exceed a pressure which is obtained by adding a substantially constant pressure to a set pressure depending upon an input current to a proportional solenoid 38, and a flow control valve 40 is located below the pilot valve 30. Further, in the relief valve 14, a pressure receiving surface Fp of the valve element 15 facing a pressurizing chamber 19 receives the pressure of pilot fluid Lp, and a lower side pressure receiving surface Fm receives the pressure of main circuit fluid Lm. In this arrangement, the area of the pressure receiving surface Fp is set to be K times as large as that of the pressure receiving surface Fm, and the side pressure surface of the valve element 15 is communicated with a drain line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot-operated pressure control valve, and more specifically, a proportional solenoid type pressure control valve is used as a pilot valve, and a pilot fluid output from the proportional solenoid type pressure control valve is used. The present invention relates to a pilot operated pressure control valve that opens and closes a pressure control valve such as a relief valve to control the pressure of a main circuit fluid.

[0002]

2. Description of the Related Art A conventional electromagnetic type flow control valve of this type is shown in FIG. In FIG. 12, 11 is an inflow port,
Reference numeral 12 is a return port, 13 is a drain port, and 14 is a relief valve. Reference numeral 15 is a valve body of the relief valve 14, 16 is a valve cylinder, and 17 is a spring. Reference numeral 20 is a manual pressure control valve, and 30 is an electromagnetic pilot valve. 38 is a proportional solenoid of the pilot valve 30, 39 is an amateur. Also, r1
, R2 are throttles, Lm is the main circuit fluid, Lp is the pilot fluid, and Pm is the set pressure.

In the conventional apparatus having such a configuration, the set pressure Pm that determines the operating point of the relief valve 14 is set in advance by the input current of the proportional solenoid 38 of the pilot valve 30. In the normal state, the relief valve 14, the manual pressure control valve 20, and the pilot valve 30 are all maintained in the equilibrium state as shown in the figure. When the pressure of the main circuit fluid Lm rises, a flow is generated in the pilot fluid Lp and a differential pressure is generated before and after the throttle r1 and the valve element 15 of the relief valve 14 is generated.
The pressure to push down becomes weaker.

When the pressure of the main circuit fluid Lm exceeds a certain pressure Ps, the balance of the relief valve 14 is lost, the valve element 15 moves upward, the valve seat 18 is opened, and the main circuit fluid Lm flows back to T. After that, the pressure of the main circuit fluid Lm is reduced and the pushing force of the pilot fluid Lp is reduced, and the valve seat is closed again. In this way, the relief valve 14 operates so that the maximum pressure of the main circuit fluid Lm is controlled so as not to exceed the set pressure Ps.

[0005]

The maximum thrust of the small proportional solenoid 38 used for this type of pressure control is usually about 5 to 10 Kgf [approximately 50 to 100 N (Newton)]. As described above, the conventional electromagnetic pressure control valve balances the thrust generated by the proportional solenoid 38, the pressure of the pilot fluid Lp acting on the effective area of the poppet, and the elastic force of the balancing spring to set the set pressure Ps. After being set, the pressure of the main circuit fluid Lm is controlled by the set pressure Ps.

However, in order to improve the responsiveness of the conventional electromagnetic type flow control valve and to control the pressure of the main circuit fluid Lm of higher pressure, a large proportional solenoid 38 having a large thrust is attached to the pilot valve 30. It may be necessary to use or reduce the effective area of the seat and poppet.

However, when the large proportional solenoid 38 is used, the entire structure of the valve becomes large, which causes a cost increase. Further, the inductance of the proportional solenoid 38 increases and the weight of the armature 39 also increases, which adversely affects the responsiveness. On the other hand, if the effective area of the poppet is reduced, the shape of the seat that constitutes the poppet and the valve seat also becomes smaller, and the taper of the poppet and the hole of the seat hole must be processed with high precision in a small size. There are difficulties in processing technology. In addition, the flow rate of the pilot fluid Lp decreases as the diameter of the seat hole and the throttle r1 decreases, and the response is further delayed, and various problems such as the influence of foreign substances such as dust mixed in the pilot fluid are caused. There was a point.

The present invention has been made in order to solve such a problem of the conventional device, and the pressure receiving surface of the pilot fluid in the main valve for controlling the main circuit fluid is K times as large as the pressure receiving surface of the main circuit fluid. It is intended to realize a pilot operated pressure control valve capable of controlling the pressure of the main circuit fluid Lm of K times high pressure by using the electromagnetic pressure control valve equivalent to the conventional one. is there.

[0009]

According to the present invention, there is provided a proportional electromagnetic pilot valve, a flow control valve comprising an orifice for supplying pilot fluid introduced from a main circuit fluid to the pilot valve and a pressure reducing type pressure compensating valve. In a pilot operated pressure control valve equipped with a pressure control valve for controlling the pressure of the main circuit fluid in accordance with the input current of the pilot valve, in the pressure control valve, the pilot fluid pressure receiving surface Fp of the valve body and the main circuit fluid The pressure receiving surface Fm and Fp = KFm are formed, and
This is a pilot operated pressure control valve in which the side pressure surface of the valve body communicates with a drain. In addition, a pilot operated pressure control valve is provided in which a filtering means having a plurality of fine holes is provided at the input end of the flow rate adjusting valve. Further, the pilot operated pressure control valve is provided with a regulating means for regulating the return flow in the return passage of the relief valve.
In addition, a pilot operated pressure control valve is provided which is provided with a filtering means having a plurality of pores at the input end of the flow rate adjusting valve and a regulating means for regulating the return flow in the return passage of the relief valve. is there.

Further, according to the present invention, an electromagnetic pilot valve, a flow rate adjusting valve including an orifice and a pressure reducing type pressure compensating valve for supplying pilot fluid introduced from an external fluid pressure source to the pilot valve, and an input of the pilot valve In a pilot operated pressure control valve equipped with a pressure control valve that controls the pressure of the main circuit fluid in response to an electric current, in the pressure control valve, the pilot fluid pressure receiving surface Fp of the valve body and the main circuit fluid pressure receiving surface F
m and Fp = KFm, and a pilot operated pressure control valve in which the side pressure surface of the valve element communicates with the drain. In addition, a pilot operated pressure control valve is provided in which a filtering means having a plurality of fine holes is provided at the input end of the flow rate adjusting valve. Further, the pilot operated pressure control valve is provided with a regulating means for regulating the return flow in the return passage of the relief valve. Further, a pilot-operated pressure control valve is provided in which a filtering means having a plurality of pores is provided at the input end of the flow rate adjusting valve, and a regulating means for regulating the return flow in the return passage of the relief valve is provided. is there.

[0011]

The pilot fluid, which is the set pressure of the pilot valve, is supplied to the pressurizing chamber of the relief valve through the pilot flow passage which is connected to the output side of the series type flow control valve and which is provided with a throttle. In a normal state, the poppet of the pilot valve closes the seat hole, the spool of the flow rate adjusting valve remains at a fixed position in the sleeve, and the valve seat of the relief valve is closed to maintain the equilibrium state.

When the pressure of the main circuit fluid increases, the pressure of the pilot fluid also rises, and a differential pressure is generated before and after the throttle provided in the pilot flow passage added to the relief valve, and the pressure of the pilot fluid that presses the relief valve is increased. Weakened. Further, when the pressure of the main circuit fluid rises and exceeds the set pressure, the valve body of the relief valve moves, the valve seat is opened, and the main circuit fluid flows out to the return side. After that, when the pressure decreases due to the outflow of the main circuit fluid, the pressure of the pilot fluid also decreases and the valve seat is closed again. Thus, the relief valve operates so that the maximum pressure of the main circuit fluid is controlled so as not to exceed the set pressure.

In the present invention, in particular, the upper pressure-receiving surface of the valve body of the relief valve is made K times as large as the lower pressure-receiving surface. The pressure receiving surface of the valve body facing the pressure chamber is applied with the pressure of the pilot fluid, the pressure receiving surface of the lower side is applied with the fluid pressure of the main circuit fluid, and the side pressure surface is configured to communicate with the drain. ing. As a result, the pressure of the main circuit fluid, which is K times higher in pressure, is controlled, regardless of the use of a pilot valve having a thrust and a rating that are comparable to those in the past.

[0014]

【Example】

Embodiment 1 FIG. 1 is an explanatory view of a configuration of an embodiment of the present invention, FIG. 2 is an enlarged view of a flow rate adjusting valve of Embodiment 1 of the present invention, and FIG.
FIG. 4 is a detailed fluid circuit diagram of FIG. 1.
In each of the drawings of the embodiments of the present invention, the same parts as those of the conventional device are denoted by the same reference numerals, and the description will be partially duplicated but will be described in a little more detail.

In FIG. 1, 1 is a first housing, 2 is a second housing, 3 is a third housing, and Lm and Lp are the same main circuit fluid and pilot fluid as described above. Reference numerals 11 and 12 denote inlets and return ports for the main circuit fluid Lm provided in the first housing 1, 13 denotes a drain port for the pilot fluid Lp, and 14 denotes a relief valve.
The relief valve 14 is composed of a valve body 15, a valve cylinder 16 and a spring 17, and is incorporated in a connecting portion of the first casing 1 and the second casing 2 in a cartridge-type compatible manner. Reference numeral 18 is a valve seat of the relief valve 14, and 19 is a pressurizing chamber formed on the upper surface side of the valve body 15. The valve seat 18 of the relief valve 14 is the valve body 1
5 and the edge portion of the valve cylinder 16 are formed.

The valve body 15 of the relief valve 14 is formed in a substantially T-shape, and is inserted together with the spring 17 in a sliding hole of the same shape formed in the central portion of the valve cylinder 16 so as to be vertically slidable. There is. The pressure of the pilot fluid Lp is applied to the pressure receiving surface Fp formed by the horizontal surface of the valve body 15 facing the pressurizing chamber 19,
The fluid pressure of the main circuit fluid Lm is applied to the pressure receiving surface Fm on the lower surface side, and the side pressure surface [(K-1) F] is communicated with the drain port 13. Here, in particular, the pressure receiving surface Fp is made to be K (K> 1) times the pressure receiving surface Fm. The relief valve 14 is opened and closed according to the pressure of the main circuit fluid Lm, and the valve seat 1
When 8 is opened, the main circuit fluid L flowing from the inlet 11
m is discharged from the return port 12.

Reference numeral 30 denotes a proportional electromagnetic pilot valve, which is the second
It is arranged on the upper part of the housing 2. 31 is a seat (seat ...
Valve seat), 32 is a seat hole, 33 is a conical poppet (PO
PPET ... Lift valve), 34 is a balance spring, and 35 is a push rod. 36 is an input chamber in which the seat 31 is arranged, and 37 is a drain chamber in which the poppet 33, the balance spring 34 and the push rod 35 are arranged. Further, 38 is a proportional solenoid provided in the third housing 3, and 39 is an amateur.
The pilot valve 30 sets a set pressure Ps according to the input current of the proportional solenoid 38 so that the pressure of the main circuit fluid Lm does not exceed the pressure (almost one force of the spring 17) which is a substantially constant pressure applied to the set pressure Ps. It is controlled in the same manner as in the conventional device described above.

Reference numeral 40 is a series type flow rate adjusting valve. The flow rate adjusting valve 40 is provided below the pilot valve 30. Reference numeral 41 is a sleeve of the flow rate adjusting valve 40, 42 is a spool that slides in the sleeve 41, and 43 is an addition spring. Four
4 and 45 are inflow holes and outflow holes provided in the sleeve 41,
46 is an orifice, 47 is a side passage, and 48 is an internal passage of the spool 42. The outflow hole 45 corresponds to the pilot valve 30.
Is connected to the input chamber 36. Further, the hole diameter of the internal flow passage 48 is formed to be slightly larger than the orifice 46 and the side passage 47. 49 is a pressure receiving chamber formed on the right side in the sliding hole of the spool 42, 51 is a cylindrical flow passage formed in the central portion, and 52 is a spring chamber in which the addition spring 43 is arranged.

The pressure receiving chamber 49 is connected to the flow passage 51 through the internal flow passage 48, and the spring chamber 52 is connected to the side passage 47 and the orifice 4.
It communicates with the flow path 51 via 6. That is, the input pressure of the pilot fluid Lp to the orifice 46 is the internal flow path 48.
Is applied to the pressure receiving chamber 49 via the side passage 47, and the output pressure is guided to the spring chamber 52 via the side passage 47. The series type flow control valve 40 operates so that the pressure on both sides of the orifice 46 is always constant, compensating for the pressure fluctuation of the pilot fluid Lp and the input pressure to the orifice 46 with respect to the set pressure Ps. Addition value determined by the spring constant of the addition spring 43 [normal,
The pressure is controlled to be 0.2 to 0.6 Mpa (Mega-Pascal)].

Reference symbols p1 to p3 are pilot flow passages through which the pilot fluid Lp flows, d1 and d2 are drain flow passages through which the drain Ld flows, and r2 is a throttle. The pilot flow path p1 opens to the inlet 11, and part of the main circuit fluid Lm flows into the pilot flow path p1. Reference numerals t and T are tanks for storing drains and returns, and have the same reference numerals as those of the above-mentioned conventional device.

The operation of the embodiment of the present invention having the above construction will be described below. As shown in the drawing, the pressurizing chamber 19 of the relief valve 14 has an outflow hole 45 of the series type flow control valve 40.
A pilot fluid Lp is supplied through a pilot flow path p3 connected to the valve and provided with a restriction r2. The pilot fluid Lp is also supplied to the input chamber 36 of the pilot valve 30 via the pilot flow path p2 branched from the outflow hole 45. In the normal state, the poppet 33 of the pilot valve 30 closes the seat hole 32, and the relative positional relationship between the spool 42 of the flow rate adjusting valve 40 and the sleeve 41 is in the state shown in the figure, and the valve seat of the relief valve 14 is in the state. 18
Is closed and equilibrium is maintained.

Here, when the pressure of the main circuit fluid Lm increases, the pressure of the pilot fluid Lp also rises, and this increased pilot fluid Lp flows into the flow passage 51 through the inflow hole 44 of the series type flow control valve 40. . At this time, a differential pressure is generated before and after the orifice 46 in the sleeve 41,
The pressure on the spring chamber 52 side decreases and the pressure on the pressure receiving chamber 49 side increases. Therefore, the spool 42 is pushed to the left in the sleeve 41, and at the same time, the valve seat formed by the sleeve 41 and the edge portion of the spool 42 is closed to reduce the pressure of the pilot fluid Lp. As a result, a new equilibrium state is maintained while the pilot fluid Lp is depressurized.

When the pressure of the pilot fluid Lp reaches the set pressure Ps, the poppet 33 of the pilot valve 30 is pushed and the seat hole 32 is opened. At the same time, the balance of the relief valve 14 is lost, the valve body 15 moves upward, and the valve seat 18 is opened. When the valve seat 18 of the relief valve 14 is opened and the main circuit fluid Lm flows back to T, the pressure of the main circuit fluid Lm decreases. After that, the pressure of the pilot fluid Lp introduced from the side surface of the inlet 11 also decreases, and the valve seat 18 is closed again. In this way, the relief valve 14 operates so that the maximum pressure of the main circuit fluid Lm is controlled so as not to exceed the set pressure Pm, and the safety of the hydraulic equipment and the like connected to the load side is maintained. When the pressure of the main circuit fluid Lm is made higher, the input current of the proportional solenoid 38 can be increased so as to correspond to this pressure, and the pressure can be similarly controlled.

In this case, in the first embodiment of the present invention, the upper pressure-receiving surface Fp of the valve body 15 of the relief valve 14 is made double the lower pressure-receiving surface Fm K. The pressure of the pilot fluid Lp is applied to the pressure receiving surface Fp of the valve body 15 which faces the pressurizing chamber 19, and the main circuit fluid Lm is applied to the lower pressure receiving surface Fm.
Fluid pressure is applied, and the lateral pressure surface communicates with the drain port 13. As a result, despite using a pilot valve with a thrust and rating equivalent to the conventional one,
It is possible to realize a pilot operated pressure control valve capable of controlling the main circuit fluid Lm that is K times higher in pressure.

On the other hand, the internal passage 48 of the spool 42 of the flow rate adjusting valve 40 for supplying the pilot fluid Lp to the pilot valve 30 has a hole diameter slightly larger than that of the orifice 46 and the side passage 47 forming the throttle mechanism as described above. Has been done.
Therefore, if the orifice 46 or the side passage 47 is clogged, the raised pilot fluid Lp is guided to the pressure receiving chamber 49 to displace the spool 42 toward the spring chamber 52. As a result, the spool 42 and the sleeve 41
Of the pilot fluid Lp
The output of is reduced and is guided to the safe side.

Second Embodiment FIG. 5 is an explanatory diagram of the configuration of the second embodiment of the present invention, and FIG. 6 is a connection diagram showing the circuit configuration of FIG. In the second embodiment of the present invention,
Unlike the first embodiment, the main circuit fluid Lm is not used as the pilot fluid Lp. Instead, a separate line Pd is constructed for the pilot fluid Lp. This Example 2
According to the configuration described above, since the pilot fluid Lp containing a stable pressure and containing no impurities is supplied through the separate line Pd, there is almost no trouble caused by foreign matter in the oil, and a more stable pressure control can be achieved. be able to.

Third Embodiment FIG. 7 is a structural explanatory view of a third embodiment of the present invention, and its circuit configuration is shown in FIG. In the third embodiment, in addition to the configuration of the first embodiment, the series type flow rate adjusting valve 40 is improved. In FIG. 7, 61 and 62 are two bushes of similar structure. 63 is a flange of both bushes 61 and 62, 64 is a plurality of pores provided in the axial direction. The pores 64 are formed to have a smaller diameter than the orifice 46 and the side passage 47. The bushes 61, 62 having a plurality of pores 62 constitute a throttling mechanism 60 having a filtering function, and are respectively connected to the two inflow holes 44 provided on the input side of the pilot fluid Pm of the flow rate adjusting valve 40. It is fitted.

According to the configuration of the third embodiment of the present invention in which the bushes 61, 62 having a plurality of pores 64 are arranged in parallel on the input side of the flow rate adjusting valve 40 for the pilot fluid Pm, the fluid is mixed into the pilot fluid Pm. Pilot flow path L for foreign substances
Inflow to p is prevented. Therefore, the pilot flow path L
There is an advantage that the fluid circuit elements such as the orifice 46 arranged in p and the side passage 47 leading to the spring chamber 52 are not clogged, and wasteful time such as operation stop for inspection and adjustment can be prevented. As shown in the figure, the diameter of the pores 64 is 0.3-0.8
According to the prototype of the example in which about 5 pieces (10 pieces in total) are provided,
It was confirmed that the probability of clogging of all 10 pores 64 was low.

Fourth Embodiment FIG. 9 is an explanatory diagram of the configuration of a fourth embodiment of the present invention, and FIG. 10 is an operation explanatory diagram thereof. In FIG. 9, 71, 72 and 73
Are an annular chamber, a cylindrical chamber, and a radial radiation chamber provided in the relief valve 14. Due to the annular chamber 71, the cylindrical chamber 72, and the radiation chamber 73, the main circuit fluid Lm flowing out from the valve seat 18
A restriction mechanism 70 is configured to restrict the flow direction of the return flow and the dynamic pressure to restrict the flow. In the fourth embodiment of the present invention having such a configuration, the pressure of the main circuit fluid Lm is set to the set pressure Pm.
When [Pm = Ps + α (α = spring force)] is exceeded, the valve body 15 is displaced upward against the downward force of the pilot fluid Lp that pushes the pressure receiving surface Fp. Then, the valve seat 18 formed by the edge portion of the valve body 15 and the valve cylinder 16 is opened, and the main circuit fluid Lm flows out from the discharge port 12 and is discharged to the tank T.

At this time, the main circuit fluid Lm having passed through the valve seat 18 flows into the annular chamber 71 which is made slightly wider, and
As shown in FIG. 7, the flow direction is changed while being slightly released and bent, and the mixture is stirred in the annular chamber 71 and flows into the next cylindrical chamber 72. The fluid in the cylindrical chamber 72, which is narrower than the annular chamber 71 and has a longer flow path, is compressed in the radial direction and rises along the axial direction of the valve body 15. Then, the main circuit fluid Lm reaching the upper part of the cylindrical chamber 72 is redirected here to be branched into the radiation chamber 73 provided at a right angle, and then transferred to the tank T via the return port 12. As a result, the flow of the main circuit fluid Lm that rapidly returns and flows out of the return flow path with the opening of the valve seat 18 is regulated by the regulation mechanism 70, and the fluid noise generated by the flow returned to the tank T is prevented. You can

FIG. 11 is an application example in which the third embodiment and the fourth embodiment are combined, and the relief valve 14 and the series type flow rate adjusting valve 40 are respectively provided with a restricting mechanism 70 and a filtering function as shown by hatching. A mechanism 60 is provided. In the configuration of the application example of FIG. 11, not only the combined operation of the third and fourth embodiments but also the effect thereof is a superposition of both embodiments, so the description of the operation and effect of FIG. 11 is omitted. To do.

In the above embodiment, the valve body 15 is used as the valve cylinder 1.
The case where the pressure of the main circuit fluid Lm is maintained at a constant value or less by using the relief valve 14 for opening and closing 6 has been described as an example, but a balance piston type relief valve or a pressure reducing valve may be used. Further, although the conical cone-shaped poppet 33 is used for the pilot valve 30 in each embodiment, the seat hole 32 may be opened and closed with a spherical poppet, in short, the pilot fluid pressure receiving surface of the valve body for opening and closing the main circuit fluid. May be K times the pressure receiving surface of the main circuit fluid. Further, although the description has been given of the case where the orifice of the sleeve of the flow rate adjusting valve is built in, the orifice may be provided in another portion.

[0033]

The present invention has an electromagnetic pilot valve and
The pilot valve was equipped with a flow control valve that rubs the pilot fluid guided from the main circuit fluid under reduced pressure and supplies a constant flow rate, and a pressure control valve that controls the pressure of the main circuit fluid in response to the input current of the pilot valve. In the pilot operated pressure control valve, the pressure receiving surface Fp of the pilot fluid and the pressure receiving surface Fm of the main circuit fluid of the valve body in the pressure control valve are set to Fp = KF
A pilot operated pressure control valve was constructed in which the side pressure surface of the valve body was made to communicate with the drain while being configured to m (K> 1).
In addition, a pilot operated pressure control valve is provided in which a filtering means having a plurality of fine holes is provided at the input end of the flow rate adjusting valve. Further, a pilot operated pressure control valve is provided which is provided with a regulating means for regulating the return flow in the return passage of the relief valve.
In addition, a pilot operated pressure control valve is provided in which a filtering means having a plurality of pores is provided at the input end of the flow rate adjusting valve and a regulating means for regulating the return flow in the return passage of the relief valve is provided.

Further, the present invention corresponds to an electromagnetic pilot valve, a flow rate adjusting valve for supplying a constant flow rate to the pilot valve by depressurizing the pilot fluid introduced from an external fluid pressure source, and an input current of the pilot valve. In the pilot operated pressure control valve having a pressure control valve for controlling the pressure of the main circuit fluid, the pressure receiving surface Fp of the pilot fluid of the valve body and the pressure receiving surface Fm of the main circuit fluid in the pressure control valve are set to Fp.
= KFm, and a pilot operated pressure control valve in which the side pressure surface of the valve body communicates with the drain. In addition, a pilot operated pressure control valve is provided in which a filtering means having a plurality of fine holes is provided at the input end of the flow rate adjusting valve. Further, a pilot operated pressure control valve is provided which is provided with a regulating means for regulating the return flow in the return passage of the relief valve.
Further, a pilot-operated pressure control valve having a filtering means having a plurality of pores at the input end of the flow rate adjusting valve and a regulating means for regulating the return flow in the return passage of the relief valve is configured.

As a result, it becomes possible to control the pressure K times the control pressure of the pilot valve. For example, although a standard proportional electromagnetic pressure control valve is used as a pilot valve, high pressure control of about 100 MPa can be expected. Also, by disposing the filtering means with multiple small holes on the input side of the flow rate control valve in the pilot flow path, foreign matter contained in the pilot fluid can be removed, and the orifice in the fluid circuit and clogging of the throttle mechanism can be eliminated. Can be prevented. Furthermore, since a control means for adding flow resistance or regulating the flow direction is provided on the outflow side of the main circuit fluid flowing out from the main valve, the generation of fluid noise accompanied by noise due to the outflow of the high-pressure main circuit fluid is particularly prevented. It can be lost.

Therefore, according to the present invention, it is possible to provide a pilot operated pressure control valve having a contamination-proof function, having few failures and capable of controlling high pressure of the main circuit fluid.

Incidentally, when the magnification K = 4 between the pressure receiving surface Fp and the pressure receiving surface Fm, the added value of the adding spring 17 of the relief valve 14 is set.
If the pressure is 0.3 MPa, for example, the pressure of the main circuit fluid will be as follows. Main circuit fluid pressure (Pm) = (Set pressure Ps x K) + Pressure due to addition spring = (20 x 4) + 0.3 = 80.3 Mpa

[Brief description of drawings]

FIG. 1 is a configuration explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an enlarged view of the flow rate adjusting valve according to the first embodiment of the present invention.

FIG. 3 is a connection diagram showing a circuit configuration according to the first embodiment of the present invention.

FIG. 4 is a connection diagram showing a detailed circuit configuration of FIG.

FIG. 5 is a configuration explanatory diagram of a second embodiment of the present invention.

FIG. 6 is a connection diagram showing the circuit configuration of FIG.

FIG. 7 is a structural explanatory diagram of Embodiment 3 of the present invention.

8 is a connection diagram showing the circuit configuration of FIG. 7. FIG.

FIG. 9 is a structural explanatory diagram of Embodiment 4 of the present invention.

FIG. 10 is an operation explanatory diagram of the fourth embodiment of the present invention.

FIG. 11 is a structural explanatory diagram of Embodiment 5 of the present invention.

FIG. 12 is a structural explanatory view of a conventional electromagnetic pressure control valve.

FIG. 13 is a connection diagram showing a circuit configuration of a conventional electromagnetic pressure control valve.

[Explanation of symbols]

 14 Relief valve 16 Valve body 18 Valve seat 17 Adding spring 19 Pressurizing chamber 30 Pilot valve 38 Proportional solenoid 40 Flow rate adjusting valve 41 Sleeve 42 Spool 43 Adding spring 46 Orifice 47 Side passage 48 Internal passage 60 Filtering mechanism (filtering means) 61 Bush 62 Bush 64 Pore 70 Regulator mechanism (Regulator) p1 to p3 Pilot channel d1 to d3 Return channel r1 to r2 Restriction Pd Separate line Fm Pressure receiving surface Fp Pressure receiving surface Lm Main circuit fluid Lp Pilot fluid

Claims (8)

[Claims] 1. An electromagnetic pilot valve that opens and closes a pilot flow path by driving an armature by a thrust force proportional to an input current of a solenoid to move a poppet that opposes a balance spring from and away from a seat, and a main pilot valve for the pilot valve. A series type flow control valve consisting of a throttle and a pressure reducing type pressure compensating valve that supplies a constant pilot fluid derived from the circuit fluid, and opens and closes the valve body in the valve cylinder according to the input current of the pilot valve. A pilot operated pressure control valve having a pressure control valve for controlling the pressure of a main circuit fluid, comprising: a pressure receiving surface Fp of a pilot fluid of a valve body of the pressure control valve; and a pressure receiving of a main circuit fluid opposed to the pressure receiving surface Fp. Face Fm
And Fp = KFm, and the side pressure surface of the valve body communicates with the drain. 2. The pilot operated pressure control valve according to claim 1, wherein the flow rate adjusting valve has an input end provided with a filtering means composed of a plurality of fine holes. 3. The regulating means for regulating the return flow is provided in the return passage of the relief valve.
Pilot operated pressure control valve described. 4. The flow rate adjusting valve is provided with a filtering means having a plurality of fine holes at an input end thereof, and a regulating means for regulating a return flow in a return passage of the relief valve. Item 1. A pilot operated pressure control valve according to item 1. 5. An electromagnetic pilot valve for opening and closing a pilot passage by driving an armature with a thrust force proportional to an input current of a solenoid to bring a poppet against a balance spring into and out of contact with a seat, and an external pilot valve for the pilot valve. A series type flow control valve consisting of a throttle and a pressure reducing type pressure compensating valve that supplies a constant pilot fluid derived from a fluid pressure source, and opens and closes the valve body in the valve cylinder according to the input current of the pilot valve. In a pilot operated pressure control valve equipped with a pressure control valve for controlling the pressure of the main circuit fluid, a pressure receiving surface Fp of the pilot fluid of the valve body of the pressure control valve and a main circuit fluid facing the pressure receiving surface Fp. Pressure receiving surface Fm
And Fp = KFm, and the side pressure surface of the valve body communicates with the drain. 6. The pilot operated pressure control valve according to claim 5, wherein the flow rate adjusting valve has an input end provided with a filtering means having a plurality of fine holes. 7. The regulating means for regulating the return flow is provided in the return passage of the relief valve.
Pilot operated pressure control valve described. 8. The flow rate adjusting valve is provided with a filtering means having a plurality of fine holes at an input end thereof, and a regulating means for regulating a returning flow in a return passage of the relief valve. Item 5. A pilot operated pressure control valve according to Item 5.