CN218717819U - Pilot pressure compensating valve for proportional directional valve - Google Patents
Pilot pressure compensating valve for proportional directional valve Download PDFInfo
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- CN218717819U CN218717819U CN202123443401.9U CN202123443401U CN218717819U CN 218717819 U CN218717819 U CN 218717819U CN 202123443401 U CN202123443401 U CN 202123443401U CN 218717819 U CN218717819 U CN 218717819U
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Abstract
The utility model discloses a guide's formula pressure compensating valve for proportional direction valve, include: the constant-value pressure reducing valve comprises a constant-value pressure reducing valve body and an overflow valve body, wherein a high-pressure oil inlet cavity and a low-pressure oil outlet cavity are arranged in the constant-value pressure reducing valve body, a liquid inlet cavity and a liquid outlet cavity are arranged in the overflow valve body, the liquid inlet cavity and the liquid outlet cavity can be connected through an overflow valve body of the overflow valve body and an overflow port between overflow valve cores, the liquid inlet cavity is connected to the spring side of the pressure reducing valve core and externally connected with the inlet pressure of the proportional direction valve, the inlet pressure of the proportional direction valve acts on the spring-free side of the overflow valve core, and the spring side of the overflow valve core is externally connected with the outlet pressure of the proportional direction valve. The utility model discloses an overflow valve carries out signal comparison, carries out pressure compensation through the definite value relief pressure valve, makes the proportional direction valve advance, export pressure differential keep invariable.
Description
Technical Field
The utility model belongs to the technical field of the valve accuse, more specifically relates to a pilot-operated formula pressure compensating valve for proportional direction valve.
Background
The proportional directional valve can adjust the flow rate proportionally according to the size of the opening, but generally has no pressure compensation performance, and the flow rate of the controlled liquid flow is not proportional to the opening amount when pressure fluctuates. In the valve control system, the pressure compensation valve mainly refers to a constant differential pressure reducing valve of a two-way regulating valve and a constant differential overflow valve of a three-way speed regulating valve, signals for comparison are directly acted on two ends of a valve core, pressure compensation is realized through the opening size of the valve core and a valve body, and when the flow rate of the system changes greatly, the influence of hydraulic power on a valve core pressure compensation port is large, and the system belongs to direct-acting pressure compensation.
Therefore, it is desirable to develop a pilot-operated pressure compensation valve for a proportional directional valve, which prevents the pressure fluctuation of the liquid flow entering the proportional directional valve from being too large, and maintains the pressure difference between the inlet and the outlet of the proportional directional valve constant.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a guide's formula pressure compensating valve for proportional direction valve solves current proportional direction valve because the undulant great problem that leads to export flow and case opening disproportionate of business turn over hydraulic fluid port pressure differential.
In order to achieve the above object, the present invention provides a pilot-operated pressure compensating valve for a proportional directional valve, including:
the constant-value pressure reducing valve is internally provided with a high-pressure oil inlet cavity and a low-pressure oil outlet cavity, the high-pressure oil inlet cavity and the low-pressure oil outlet cavity are communicated through a pressure reducing throttling port between a pressure reducing valve body and a pressure reducing valve core of the constant-value pressure reducing valve, the pressure of the low-pressure oil outlet cavity acts on the spring-free side of the pressure reducing valve core and is transmitted to the spring side of the pressure reducing valve core through a central hole of the pressure reducing valve core, and the low-pressure oil outlet cavity is connected with an inlet of a proportional directional valve;
the overflow valve is internally provided with a liquid inlet cavity and a liquid discharge cavity, the liquid inlet cavity and the liquid discharge cavity can be connected through an overflow port between an overflow valve body of the overflow valve and an overflow valve core, the pressure of the liquid inlet cavity acts on the overflow valve core, the liquid inlet cavity is connected to the spring side of the pressure reduction valve core and is externally connected with the inlet pressure of the proportional directional valve, and the spring side of the overflow valve core is externally connected with the outlet pressure of the proportional directional valve;
when the pressure of the spring-free side of the overflow valve is larger than the pressure of the spring-side of the overflow valve, the overflow port is opened, and the liquid inlet cavity is communicated with the liquid outlet cavity.
Optionally, the overflow valve is connected to the constant value pressure reducing valve through the transition plate, a bleed hole is formed in the constant value pressure reducing valve, and a first interface is formed in the transition plate;
the transition plate is provided with a first oil duct, a second oil duct and a third oil duct;
the first oil duct is communicated between the spring side of the pressure reducing valve core and the liquid inlet cavity of the overflow valve;
the second oil duct communicates a liquid discharge cavity of the overflow valve with a discharge port on the constant value pressure reducing valve;
one end of the third oil duct is connected to the spring side of the overflow valve core, the other end of the third oil duct is connected to the first interface, and the first interface is used for being connected to the liquid outlet of the proportional directional valve.
Optionally, the fixed-value pressure reducing valve comprises a pressure reducing valve body, a pressure reducing valve core, a pressure reducing spring, a spring seat and an end cover;
the pressure reducing valve body is provided with a pressure reducing valve core hole, the pressure reducing valve core is arranged in the pressure reducing valve core hole, the end cover and the spring seat respectively seal two ends of the pressure reducing valve core hole, the pressure reducing spring is arranged in the pressure reducing valve core hole and connected between the spring seat and the constant value pressure reducing valve core, and the constant value pressure reducing valve core is abutted against the end cover under the elastic force action of the constant value pressure reducing valve spring so as to enable the opening degree of the pressure reducing throttling port to be maximum.
Optionally, a first through hole is formed in the end cover, one end of the low pressure oil outlet cavity extends to the inner side surface of the end cover to communicate with the springless side of the pressure reducing valve core, and the other end of the first through hole extends to the outer side surface of the end cover and is sealed by a sealing element;
and a low-pressure oil outlet cavity of the constant-value pressure reducing valve is communicated with the first through hole through a fourth oil duct.
Optionally, a first central hole is formed in the pressure reducing valve core along the axial direction of the pressure reducing valve core, and the first central hole communicates the non-spring side of the pressure reducing valve core with the spring side of the pressure reducing valve core;
the first center hole is connected with the through hole through a damping hole.
Optionally, a damping is provided in the fourth oil passage.
Optionally, the overflow valve comprises an overflow valve body, an overflow valve core, an overflow spring, a plug and an adjusting screw;
the overflow valve body is provided with an overflow valve core hole, the overflow valve core is arranged in the overflow valve core hole, the plug and the adjusting screw are respectively sealed at two ends of the overflow valve core hole, the overflow spring is arranged in the overflow valve core hole and is connected with the overflow valve core and the adjusting screw, and an overflow port between the overflow valve body and the overflow valve core is closed under the supporting action of the overflow spring.
Optionally, a second through hole is formed in the plug, one end of the second through hole penetrates through the plug and extends into the relief valve body, and a connector is arranged at the other end of the second through hole and used for being connected with an inlet of the proportional directional valve.
Optionally, the fixed-value pressure reducing valve is plate-shaped, an oil inlet and an oil outlet are respectively arranged on the top surface and the bottom surface of the fixed-value pressure reducing valve, the oil inlet is connected to the high-pressure oil inlet cavity, and the oil outlet is connected to the low-pressure oil outlet cavity.
Optionally, four working oil holes are respectively arranged on the bottom surface and the top surface of the constant value pressure reducing valve.
The beneficial effects of the utility model reside in that: when the pilot type pressure compensation valve for the proportional direction valve is used, when the pressure of the spring-free side of the overflow valve (namely the pressure in the low-pressure oil outlet cavity of the constant-pressure-difference pressure reduction valve, namely the inlet pressure of the proportional direction valve) is larger than the pressure of the spring-free side of the overflow valve (namely the sum of the outlet pressure of the proportional direction valve and the spring supporting force on the overflow valve core), the overflow port is opened, the liquid inlet cavity is communicated with the liquid discharge cavity, at the moment, the spring-side pressure of the pressure reduction valve core is discharged into the liquid discharge cavity from the liquid inlet cavity, the pressure of the spring-side of the pressure reduction valve core is suddenly reduced, the pressure of the spring-free side of the pressure reduction valve core is unchanged, the pressure reduction valve core moves towards the spring side, the flow area of the throttling port is reduced, even if the pressure of the low-pressure oil outlet cavity is reduced, the inlet pressure of the proportional direction valve is reduced, and the pressure difference between the liquid inlet and the liquid outlet of the proportional direction valve is kept constant. The constant-value pressure reducing valve and the overflow valve are combined to form a pilot type structure, the overflow valve performs signal comparison, the main pressure reducing valve performs pressure compensation, signals of the proportional directional valve are not interfered by hydraulic power on a valve core, the adjusting precision is high, the requirement of low pressure difference constancy can be met, and the constant-value pressure reducing valve is not influenced by the hydraulic power on the valve core basically when the flow rate is large.
Other features and advantages of the present invention will be described in detail in the detailed description which follows.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout the exemplary embodiments of the present invention.
Fig. 1 shows a perspective view of a pilot operated pressure compensating valve for a proportional directional valve according to an embodiment of the present invention.
Fig. 2 shows a front structural cross-sectional view of a pilot operated pressure compensating valve for a proportional directional valve according to an embodiment of the present invention.
Fig. 3 shows a top view of a pilot operated pressure compensating valve for a proportional directional valve according to an embodiment of the present invention.
Fig. 4 shows a top view structural cross-sectional view of a pilot operated pressure compensating valve for a proportional directional valve according to an embodiment of the present invention.
Fig. 5 shows a schematic diagram of a pilot operated pressure compensating valve for a proportional directional valve according to an embodiment of the present invention.
Description of the reference numerals
1. A pressure reducing valve body; 2. an end cap; 3. a pressure reducing valve core; 4. a pressure reducing spring; 5. a spring seat; 6. a transition plate; 7. an overflow valve; 8. a fourth oil passage; 9. a first damping; 10. a damping hole; 11. an oil drainage port;
6.1, a first oil duct; 6.2, a second oil duct; 6.3, a third oil duct; 6.4, a first interface;
7.1, an overflow valve body; 7.2, an overflow valve core; 7.3, an overflow spring; 7.4, plugging by screws; 7.5, adjusting bolts; 7.6 a second interface; 7.7, second damping; 7.8 and third damping.
Detailed Description
Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.
The utility model discloses a guide's formula pressure compensating valve for proportional direction valve, include:
the constant value pressure reducing valve is internally provided with a high-pressure oil inlet cavity and a low-pressure oil outlet cavity, the high-pressure oil inlet cavity and the low-pressure oil outlet cavity are communicated through a pressure reducing throttling port between a pressure reducing valve body of the constant value pressure reducing valve and a pressure reducing valve core, the pressure of a low-pressure oil outlet cavity acts on the spring-free side of the pressure reducing valve core and is transmitted to the spring side of the pressure reducing valve core through a central hole of the pressure reducing valve core, and the low-pressure oil outlet cavity is connected with an inlet of the proportional directional valve;
the overflow valve is internally provided with a liquid inlet cavity and a liquid discharge cavity, the liquid inlet cavity and the liquid discharge cavity can be connected with an overflow port between an overflow valve body and an overflow valve core of the overflow valve, the pressure of the liquid inlet cavity acts on the overflow valve core, the liquid inlet cavity is connected to the spring side of the pressure reduction valve core and externally connected with the inlet pressure of the proportional directional valve, and the spring side of the overflow valve core is externally connected with the outlet pressure of the proportional directional valve;
when the pressure of the spring-free side of the overflow valve is larger than the pressure of the spring-side of the overflow valve, the overflow port is opened, and the liquid inlet cavity is communicated with the liquid outlet cavity.
Specifically, when the pilot-operated pressure compensation valve for the proportional direction valve in the scheme is used, when the pressure of the spring-free side of the overflow valve (namely the pressure in the low-pressure oil outlet chamber of the constant-value pressure reducing valve, namely the inlet pressure of the proportional direction valve) is greater than the pressure of the spring-free side of the overflow valve (namely the sum of the outlet pressure of the proportional direction valve and the spring supporting force on the overflow valve core), the overflow port is opened, the liquid inlet chamber is communicated with the liquid discharge chamber, at the moment, the spring-side pressure of the pressure reducing valve core is discharged into the liquid discharge chamber from the liquid inlet chamber, the pressure of the spring-side of the pressure reducing valve core is suddenly reduced, and the pressure of the spring-free side of the pressure reducing valve core is unchanged, so that the pressure reducing valve core moves towards the spring side, the flow area of the throttling port is reduced, even if the pressure of the low-pressure oil outlet chamber is reduced, the inlet pressure of the proportional direction valve is reduced, and the pressure difference between the liquid inlet and the liquid outlet of the proportional direction valve is kept constant.
The constant-value pressure reducing valve and the overflow valve are combined to form a pilot type structure, the overflow valve performs signal comparison, the main constant-value pressure reducing valve performs pressure compensation, signals of the proportional directional valve are not interfered by hydraulic force on a valve core of the pressure compensation valve, the adjusting precision is high, the requirement of low pressure difference constancy can be met, and the constant-value pressure reducing valve is basically not influenced by the hydraulic force on the valve core when the flow is large.
As an alternative scheme, the overflow valve is connected to a constant value pressure reducing valve through a transition plate, a discharge port is arranged on the constant value pressure reducing valve, and a first connector is arranged on the transition plate;
the transition plate is provided with a first oil duct, a second oil duct and a third oil duct;
the first oil duct is communicated between the spring side of the pressure reducing valve core and the liquid inlet cavity of the overflow valve;
the second oil duct connects the liquid discharge cavity of the overflow valve with an oil discharge port on the constant value pressure reducing valve;
one end of the third oil duct is connected to the spring side of the overflow valve core, the other end of the third oil duct is connected to the first connector, and the first connector is used for being connected to a liquid outlet of the proportional direction valve.
Specifically, the overflow valve and the constant value pressure reducing valve are connected into a whole through the transition plate, so that the installation is convenient.
As an alternative scheme, the constant-value pressure reducing valve comprises a pressure reducing valve body, a pressure reducing valve core, a pressure reducing spring, a spring seat and an end cover;
the pressure reducing valve body is internally provided with a pressure reducing valve core hole, the pressure reducing valve core is arranged in the pressure reducing valve core hole, the end covers and the spring seats respectively seal two ends of the pressure reducing valve core hole, the pressure reducing spring is arranged in the pressure reducing valve core hole and is connected between the spring seat and the fixed-difference pressure reducing valve core, and the fixed-value pressure reducing valve core is abutted against the end covers under the elastic action of the fixed-value pressure reducing valve spring, so that the opening degree of the pressure reducing throttling port is maximum.
As an alternative scheme, a first through hole is formed in the end cover, one end of the low pressure oil outlet cavity extends to the inner side surface of the end cover to be communicated with the spring-free side of the pressure reducing valve core, and the other end of the first through hole extends to the outer side surface of the end cover and is sealed through a sealing piece;
and a low-pressure oil outlet cavity of the constant-value pressure reducing valve is communicated with the first through hole through a fourth oil duct.
As an alternative scheme, a first central hole is formed in the pressure reducing valve core along the axial direction of the pressure reducing valve core, and the first central hole enables the spring-free side of the pressure reducing valve core to be communicated with the spring side of the pressure reducing valve core;
the first center hole is connected with the through hole through the damping hole.
Alternatively, damping is provided in the fourth oil passage.
As an alternative, the overflow valve comprises an overflow valve body, an overflow valve core, an overflow spring, a plug and an adjusting screw;
the overflow valve body is provided with an overflow valve core hole, the overflow valve core is arranged in the overflow valve core hole, the plug and the adjusting screw are respectively sealed at two ends of the overflow valve core hole, the overflow spring is arranged in the overflow valve core hole and is connected with the overflow valve core and the adjusting screw, and an overflow port between the overflow valve body and the overflow valve core is closed under the supporting action of the overflow spring.
As an alternative scheme, a second through hole is formed in the plug, one end of the second through hole penetrates through the plug and extends into the overflow valve body, and a connector is arranged at the other end of the second through hole and used for being connected with an inlet of the proportional directional valve.
As an alternative scheme, the fixed value pressure reducing valve is plate-shaped, an oil inlet and an oil outlet are respectively formed in the top surface and the bottom surface of the fixed value pressure reducing valve, the oil inlet is connected to the high-pressure oil inlet cavity, and the oil outlet is connected to the low-pressure oil outlet cavity.
As an alternative, four working oil holes are respectively arranged on the bottom surface and the top surface of the constant value pressure reducing valve.
Examples
As shown in fig. 1 and 3, the pilot-operated pressure compensation valve for the proportional directional valve of the present embodiment includes a constant-value pressure reducing valve, a transition plate 6 and an overflow valve 7, wherein the overflow valve 7 is connected to the constant-value pressure reducing valve through the transition plate 6; the fixed value pressure reducing valve is plate-shaped, an oil inlet and an oil outlet are respectively arranged on the bottom surface and the top surface of the fixed value pressure reducing valve, the oil inlet is connected to the high-pressure oil inlet cavity, the oil outlet is connected to the low-pressure oil outlet cavity, and four working oil holes are respectively arranged on the bottom surface and the top surface of the fixed value pressure reducing valve.
As shown in fig. 2, the fixed-value pressure reducing valve includes a pressure reducing valve body 1, a pressure reducing valve core 3, a pressure reducing spring 4, a spring seat 5 and an end cover 2; the pressure reducing valve body 1 is provided with a pressure reducing valve core hole, the pressure reducing valve core 3 is arranged in the pressure reducing valve core hole, the end cover 2 and the spring seat 5 respectively seal two ends of the pressure reducing valve core hole, the pressure reducing spring 4 is arranged in the pressure reducing valve core hole and is connected between the spring seat 5 and the pressure reducing valve core 3, and the pressure reducing valve core 3 is abutted against the end cover 2 under the elastic action of the pressure reducing spring 4, so that the opening degree of a pressure reducing throttling port is maximized. The constant value pressure reducing valve is internally provided with a high-pressure oil inlet cavity and a low-pressure oil outlet cavity, the high-pressure oil inlet cavity and the low-pressure oil outlet cavity are communicated through a pressure reducing throttling port between a pressure reducing valve body 1 and a pressure reducing valve core 3 of the constant value pressure reducing valve, the pressure of the low-pressure oil outlet cavity acts on the spring-free side of the pressure reducing valve core 3 and is transmitted to the spring side of the pressure reducing valve core 3 through a central hole of the pressure reducing valve core 3, and the low-pressure oil outlet cavity is connected with an inlet of a proportional directional valve. As shown in fig. 2, the end cap is provided with a first through hole, one end of the first through hole extends to the inner side surface of the end cap 2 to communicate with the springless side of the pressure reducing valve core 3, and the other end extends to the outer side surface of the end cap 2 and is sealed by a sealing member. And a low-pressure oil outlet cavity of the constant-value pressure reducing valve is communicated with the first through hole through a fourth oil duct 8. In the pressure reducing valve core 3, a first central hole is arranged along the axial direction of the pressure reducing valve core 3, and the spring-free side of the pressure reducing valve core 3 is communicated with the spring side of the pressure reducing valve core 3 through the first central hole; the first central hole is connected with the through hole through a damping hole 10, and a first damper 9 is arranged in the fourth oil duct 8.
As shown in fig. 4, the relief valve 7 comprises a relief valve body 7.1, a relief valve core 7.2, a relief spring 7.3, a plug 7.4 and an adjusting screw 7.5; an overflow valve core hole is formed in the overflow valve body 7.1, the overflow valve core 7.2 is arranged in the overflow valve core hole, the plug 7.4 and the adjusting screw 7.5 are respectively sealed at two ends of the overflow valve core hole, the overflow spring 7.3 is arranged in the overflow valve core hole and is connected to the overflow valve core 7.2 and the adjusting screw 7.5, and an overflow port between the overflow valve body 7.1 and the overflow valve core 7.2 is closed under the supporting action of the overflow spring 7.3. The plug 7.4 is provided with a second through hole, one end of the second through hole penetrates through the plug 7.4 and extends into the overflow valve body 7.1, the other end of the second through hole is provided with a second connector 7.6, the second connector 7.6 is used for being connected with an inlet of a proportional direction valve, and a third damper 7.8 is arranged between the second connector 7.6 and the second through hole of the plug 7.4. A liquid inlet cavity and a liquid discharge cavity are arranged in the overflow valve 7, the liquid inlet cavity and the liquid discharge cavity can be connected with an overflow port between an overflow valve body 7.1 and an overflow valve core 7.2 of the overflow valve, the pressure of the liquid inlet cavity acts on the overflow valve core 7.2, the liquid inlet cavity is connected to the spring side of the pressure reduction valve core 3 and is externally connected with the inlet pressure of the proportional directional valve, and the spring side of the overflow valve core is externally connected with the outlet pressure of the proportional directional valve;
as shown in fig. 2 and 4, the constant-value pressure reducing valve is provided with an oil drain port 11, and the transition plate 6 is provided with a first connector 6.4; the transition plate 6 is provided with a first oil channel 6.1, a second oil channel 6.2 and a third oil channel 6.2; the first oil duct 6.1 is communicated between the spring side of the pressure reducing valve core 3 and the liquid inlet cavity of the overflow valve 7, and a second damper 7.7 is arranged in the first oil duct 6.1; the second oil duct 6.2 connects the liquid discharge cavity of the overflow valve 7 to the oil discharge port 11 on the constant value pressure reducing valve; one end of the third oil duct 6.3 is connected to the spring side of the overflow valve core 7.2, the other end is connected to the first connector 6.4, and the first connector 6.4 is connected to the liquid outlet of the proportional directional valve through an external pipeline.
Fig. 5 shows the principle of the pilot pressure compensating valve for a proportional directional valve of the present embodiment, where P1 and P2 are the signal input and output ends of a constant value pressure reducing valve, respectively, and X1 and X2 are the signal input and output ends of an overflow valve, respectively.
In the embodiment, the constant-value pressure reducing valve and the overflow valve are combined to form a pilot structure. The overflow valve carries out signal comparison, and the definite value relief valve carries out pressure compensation, and the signal comparison is not disturbed by hydraulic power on the definite value relief valve core, and the regulation precision is high, can satisfy the invariable demand of low differential pressure. When the flow passes through the large flow, compared with the background technology, the setting accuracy is basically not influenced by the hydraulic force on the pressure reducing valve core.
The signal ports X1 and X2 of the overflow valve are opened, pressure measuring points can be flexibly connected according to the specific requirements of a hydraulic system, the structure size of the pilot overflow valve core is small, and the pressure regulating spring of the overflow valve is not required to be strong, so that the pressure regulation is convenient. The damping mounting positions are arranged in the control oil passages, the damping in the oil passages can be randomly adjusted according to actual needs, the mounting mode of the bottom surface of the valve body adopts a standard 25-way plate type reversing valve mounting surface, the universality degree is high, and when the proportional directional valve is matched with a 25-way electro-hydraulic proportional directional valve for use, the pressure difference of the reversing position P → A of the proportional reversing valve and the pressure difference P → B can be ensured to be constant values, so that the linear relation between the output flow and the valve opening is ensured, and the linear relation between the output flow and an input signal is further ensured.
Taking the valve and a 25-way electro-hydraulic proportional directional valve for matching use as an example, the working process of the embodiment is as follows: during actual work, a port X1 of a signal input end of the overflow valve is connected with outlet pressure P2 (namely inlet pressure P of the proportional directional valve) of the constant-differential pressure-reducing valve, a first port on the transition plate is connected with pressure of a load A (or B) of the proportional directional valve, and pressure set by an overflow spring 7.3 is assumed to be 5bar, namely pressure difference between the ports X1 and X2 is 5bar.
When the pressure difference between the P2 port and the A (or B) port is more than 5bar, the overflow valve core is opened. At the moment of opening the overflow valve core, oil on the spring side of the pressure reducing valve core flows into an oil drainage port of the constant-value pressure reducing valve through a first oil duct, a negative covering part of the overflow valve core and an overflow valve body and a second oil duct, the spring side pressure of the pressure reducing valve core is suddenly reduced, the pressure change is not sensed on the spring-free side of the pressure reducing valve core, the pressure reducing valve core 3 moves to the right under the action of outlet pressure P2, a throttling port is reduced, the pressure of the port P2 is reduced due to the throttling effect of the throttling port, and the pressure difference between the port P2 and the port A (or the port B) is reduced to 5bar;
when the pressure difference between the port P2 and the port A (or the port B) is less than 5bar, the overflow valve core 7.2 cannot be opened, the pressure reducing valve core 3 is tightly attached to the end cover 2 under the action of the pressure reducing valve spring 4, the opening of the pressure reducing valve core 3 reaches the maximum, the outlet pressure P2 of the pressure reducing valve rises and approaches to the outlet pressure P1 of the system, and therefore the pressure difference between the port P2 and the port A (or the port B) is increased to 5bar;
the pressure compensation process is a dynamic adjustment process, so that the pressure difference between the X1 port and the X2 port is always kept at the set pressure value of the overflow valve spring 7.3, namely the pressure difference between the reversing position P → A of the proportional reversing valve and the pressure difference P → B are ensured to be constant values, the linear relation between the output flow and the valve opening is ensured, and the linear relation between the output flow and the input signal is further ensured.
While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.
Claims (10)
1. A pilot operated pressure compensating valve for a proportional directional valve, comprising:
the constant-value pressure reducing valve is internally provided with a high-pressure oil inlet cavity and a low-pressure oil outlet cavity, the high-pressure oil inlet cavity and the low-pressure oil outlet cavity are communicated through a pressure reducing throttling port between a pressure reducing valve body and a pressure reducing valve core of the constant-value pressure reducing valve, the pressure of the low-pressure oil outlet cavity acts on the spring-free side of the pressure reducing valve core and is transmitted to the spring side of the pressure reducing valve core through a central hole of the pressure reducing valve core, and the low-pressure oil outlet cavity is connected with an inlet of a proportional directional valve;
the overflow valve is internally provided with a liquid inlet cavity and a liquid discharge cavity, the liquid inlet cavity and the liquid discharge cavity can be connected through an overflow port between an overflow valve body of the overflow valve and an overflow valve core, the pressure of the liquid inlet cavity acts on the spring-free side of the overflow valve core, the liquid inlet cavity is connected to the spring side of the pressure reduction valve core and is externally connected with the inlet pressure of the proportional directional valve, and the spring side of the overflow valve core is externally connected with the outlet pressure of the proportional directional valve;
when the pressure of the spring-free side of the overflow valve core is higher than the pressure of the spring side of the overflow valve core, the overflow port is opened, and the liquid inlet cavity is communicated with the liquid outlet cavity.
2. The pilot-operated pressure compensation valve for the proportional direction valve according to claim 1, further comprising a transition plate, wherein the overflow valve is connected to the constant value pressure reducing valve through the transition plate, the constant value pressure reducing valve is provided with a discharge port, and the transition plate is provided with a first interface;
the transition plate is provided with a first oil duct, a second oil duct and a third oil duct;
the first oil duct is communicated between the spring side of the pressure reducing valve core and the liquid inlet cavity of the overflow valve;
the second oil duct connects the liquid discharge cavity of the overflow valve with a discharge port on the constant value pressure reducing valve;
one end of the third oil duct is connected to the spring side of the overflow valve core, the other end of the third oil duct is connected to the first interface, and the first interface is used for being connected with the liquid outlet of the proportional directional valve.
3. The pilot-operated pressure compensation valve for a proportional direction valve according to claim 1, wherein the constant-value pressure reducing valve comprises a pressure reducing valve body, a pressure reducing valve core, a pressure reducing spring, a spring seat and an end cover;
the pressure reducing valve body is provided with a pressure reducing valve core hole, the pressure reducing valve core is arranged in the pressure reducing valve core hole, the end cover and the spring seat respectively seal two ends of the pressure reducing valve core hole, the pressure reducing spring is arranged in the pressure reducing valve core hole and connected between the spring seat and the constant value pressure reducing valve core, and the constant value pressure reducing valve core is abutted against the end cover under the elastic force action of the constant value pressure reducing valve spring so as to enable the opening degree of the pressure reducing throttling port to be maximum.
4. The pilot-operated pressure compensating valve for a proportional directional valve as claimed in claim 3, wherein a first through hole is provided on the end cover, one end of the low pressure discharge chamber extends to an inside surface of the end cover to communicate with the springless side of the pressure reducing spool, and the other end of the first through hole extends to an outside surface of the end cover and is sealed by a sealing member;
and a low-pressure oil outlet cavity of the constant-value pressure reducing valve is communicated with the first through hole through a fourth oil duct.
5. The pilot pressure compensation valve for a proportional directional valve according to claim 4, wherein a first center hole is provided in the pressure reduction spool in an axial direction of the pressure reduction spool, the first center hole communicating a non-spring side of the pressure reduction spool with a spring side of the pressure reduction spool;
the first center hole is connected with the through hole through a damping hole.
6. The pilot pressure compensation valve for a proportional direction valve according to claim 4, wherein a damping is provided in the fourth oil passage.
7. The pilot-operated pressure compensating valve for a proportional direction valve according to claim 1, wherein the relief valve includes a relief valve body, a relief valve spool, a relief spring, a plug, and an adjusting screw;
the overflow valve body is provided with an overflow valve core hole, the overflow valve core is arranged in the overflow valve core hole, the plug and the adjusting screw are respectively sealed at two ends of the overflow valve core hole, the overflow spring is arranged in the overflow valve core hole and is connected with the overflow valve core and the adjusting screw, and an overflow port between the overflow valve body and the overflow valve core is closed under the supporting action of the overflow spring.
8. The pilot-operated pressure compensation valve for the proportional direction valve according to claim 7, wherein the plug is provided with a second through hole, one end of the second through hole penetrates through the plug and extends into the relief valve body, and the other end of the second through hole is provided with a connector which is used for connecting a liquid inlet of the proportional direction valve.
9. The pilot-operated pressure compensating valve for a proportional direction valve as claimed in claim 1, wherein the constant pressure reducing valve is plate-shaped, and an oil inlet and an oil outlet are respectively provided on a top surface and a bottom surface of the constant pressure reducing valve, the oil inlet being connected to the high pressure oil inlet chamber, and the oil outlet being connected to the low pressure oil outlet chamber.
10. The pilot pressure compensating valve for a proportional direction valve according to claim 1, wherein four working oil holes are provided on a bottom surface and a top surface of the constant pressure reducing valve, respectively.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123443401.9U CN218717819U (en) | 2021-12-30 | 2021-12-30 | Pilot pressure compensating valve for proportional directional valve |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123443401.9U CN218717819U (en) | 2021-12-30 | 2021-12-30 | Pilot pressure compensating valve for proportional directional valve |
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| Publication Number | Publication Date |
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| CN218717819U true CN218717819U (en) | 2023-03-24 |
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| CN202123443401.9U Active CN218717819U (en) | 2021-12-30 | 2021-12-30 | Pilot pressure compensating valve for proportional directional valve |
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| Country | Link |
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| CN (1) | CN218717819U (en) |
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