CN216642613U - Hydraulic logic valve block - Google Patents

Abstract

A hydraulic logic valve block comprising: the valve body is provided with a first oil port, a control port, a second oil port and an oil unloading port; the reversing valve, the first restrictor and the second restrictor are arranged in the valve body; a first oil passage connected to the first oil port and branched into a first branch passage and a second branch passage, a first restrictor being disposed in the first branch passage; a second oil passage connecting the second oil port and the first branch passage; an oil discharge passage connected to the oil discharge port; the control channel is connected between the control port and the control end of the reversing valve and used for controlling the valve position of the reversing valve; the second branch channel is communicated with or disconnected from the second oil duct through a reversing valve; the oil discharge channel is communicated or disconnected with the second oil duct through a reversing valve; the second restrictor is disposed in the oil drain passage or in an internal passage of the reversing valve establishing communication between the oil drain passage and the second oil passage. A fast response can be achieved.

Description

Hydraulic logic valve block

Technical Field

The present application relates to a hydraulic logic valve block suitable for logic control in a hydraulic system.

Background

Hydraulic systems typically employ a main valve to control the supply of hydraulic oil from a pump to an actuator, the position of the main valve being controlled electronically, hydraulically or electro-hydraulically. For pilot-controlled main valves, a pilot valve may be used to control the oil pressure at the control end of the main valve. In one prior art, a pilot valve is combined with a logic valve block to control the oil pressure at the control end of the main valve. The logic valve block has a valve element, an input port, an output port, a dump port, and a control port. The input port and the control port are connected with the pilot valve, and the output port is connected with the control end of the main valve. A restrictor is arranged between the input port and the control port. When the control port has no oil pressure or the oil pressure is lower, the valve element is in the first valve position, and all hydraulic oil of the input port flows to the output port, so that the output port outputs first pressure; when the oil pressure of the control port exceeds the valve position switching pressure, the valve element is switched to the second valve position, so that a part of the hydraulic oil of the input port flows to the output port, and the other part of the hydraulic oil flows to the oil discharge port, and the output port outputs a second pressure lower than the first pressure. In such logic valve blocks, there is always a restriction between the input port and the control port that limits the flow area of the input port into between the output ports when the valve element is in the first valve position, which may affect the response speed of the main valve.

SUMMERY OF THE UTILITY MODEL

It is an object of the present application to provide a hydraulic logic valve block that enables a large flow area when the valve element is in the first valve position to enable a fast response of the main valve controlled thereby.

To this end, the present application provides, in one aspect thereof, a hydraulic logic valve block comprising:

the valve body is provided with a first oil port, a control port, a second oil port and an oil unloading port; and

the reversing valve, the first throttling device and the second throttling device are arranged in the valve body;

wherein, hydraulic logic valve block still includes:

a first oil passage connected to the first oil port and branched into a first branch passage and a second branch passage, the first restrictor being disposed in the first branch passage;

a second oil passage connecting the second oil port and the first branch passage;

an oil discharge passage connected to the oil discharge port;

the control channel is connected between the control port and the control end of the reversing valve and used for controlling the valve position of the reversing valve;

the second branch channel is communicated with or disconnected from the second oil channel through the reversing valve;

the oil discharge channel is communicated with or disconnected from the second oil channel through the reversing valve;

the second throttling device is arranged in the oil unloading channel or in an internal channel of the reversing valve which establishes communication between the oil unloading channel and the second oil duct;

the reversing valve is used for communicating the second branch channel with the second oil duct and disconnecting the oil unloading channel with the second oil duct at the first valve position, and is used for disconnecting the second branch channel with the second oil duct and communicating the oil unloading channel with the second oil duct at the second valve position.

In one embodiment, the reversing valve is a two-position three-way valve and is provided with an oil inlet, an oil outlet and an oil drainage port, the second branch channel is connected to the oil inlet, the second oil duct is connected to the oil outlet, and the oil discharge channel is connected to the oil drainage port; at the first valve position, the oil inlet is communicated with the oil outlet, and the oil drain port is cut off; and at the second valve position, the oil inlet is cut off, and the oil outlet is communicated with the oil drainage port.

In one embodiment, the second flow restrictor is disposed within the reversing valve between the oil outlet and the oil drain below the second valve position.

In one embodiment, the reversing valve is a two-position four-way valve and is provided with an oil inlet, an oil outlet, an oil return port and an oil drainage port, a second branch channel is connected to the oil inlet, a second oil duct is connected to the oil outlet, the upstream section of the oil discharge channel is connected between the oil return port and the second oil duct, and the downstream section of the oil discharge channel is connected between the oil drainage port and the oil discharge port; at first valve position, oil inlet and oil-out intercommunication, oil return opening and draining port are all cuted by the draining port, and at second valve position, oil inlet and oil-out are all cuted, oil return opening and draining port intercommunication.

In one embodiment, the second restriction is provided in an upstream section or a downstream section of the oil discharge passage; or the second throttler is arranged between the oil return port and the oil drainage port below the second valve position in the reversing valve.

In one embodiment, the reversing valve comprises a first reversing valve and a second reversing valve, and the first reversing valve and the second reversing valve are two-position two-way valves and respectively provided with an oil inlet and an oil outlet;

the second branch channel is connected to an oil inlet of the first reversing valve, the second oil duct is connected to an oil outlet of the first reversing valve, an upstream section of the oil unloading channel is connected between the oil outlet of the second reversing valve and the second oil duct, and a downstream section of the oil unloading channel is connected between an oil inlet of the second reversing valve and the oil unloading port;

in the first valve position, an oil inlet and an oil outlet of the first reversing valve are communicated, and an oil inlet and an oil outlet of the second reversing valve are both cut off; and in the second valve position, the oil inlet and the oil outlet of the first reversing valve are both cut off, and the oil inlet and the oil outlet of the second reversing valve are communicated.

In one embodiment, the second restriction is provided in an upstream section or a downstream section of the oil discharge passage; or the second throttler is arranged between the oil inlet and the oil outlet below the second valve position in the second reversing valve.

In one embodiment, the reversing valve is a two-position four-way valve, and a valve core of the two-position four-way valve comprises four sub valve cores which are combined together, wherein each sub valve core is provided with a respective oil inlet and an oil outlet;

an oil inlet and an oil outlet of the first sub valve core are communicated, an oil inlet and an oil outlet of the second sub valve core are cut off, an oil inlet and an oil outlet of the third sub valve core are cut off, and an oil inlet of the fourth sub valve core is communicated with the oil outlet;

at the first valve position, the second branch channel is connected to the oil inlet of the first sub-valve core, the second oil duct is connected to the oil outlet of the first sub-valve core, the upstream section of the oil unloading channel is connected between the oil outlet of the third sub-valve core and the second oil duct, and the downstream section of the oil unloading channel is connected between the oil inlet of the third sub-valve core and the oil unloading port;

at the second valve position, the second branch channel is connected to the oil inlet of the second sub valve core, the second oil duct is connected to the oil outlet of the second sub valve core, the upstream section of the oil unloading channel is connected between the oil outlet of the fourth sub valve core and the second oil duct, and the downstream section of the oil unloading channel is connected between the oil inlet of the fourth sub valve core and the oil discharge channel.

In one embodiment, the second restriction is provided in an upstream section or a downstream section of the oil discharge passage; or the second throttler is arranged between the oil inlet and the oil outlet of the fourth sub-valve core in the fourth sub-valve core.

In one embodiment, the flow resistance of the first and second restrictions is adjustable, thereby adjusting the output pressure of the second port at the first and second valve positions.

According to the application, through the position of design flow controller in the hydraulic logic valve block for walk around the flow controller direct intercommunication between first hydraulic fluid port and the second hydraulic fluid port when the first valve position of valve element, the through-flow area between first hydraulic fluid port and the second hydraulic fluid port does not have the influence, when hydraulic actuator forward (process) operation, the hydraulic oil of first hydraulic fluid port does not receive the hindrance of flow controller and unobstructed flow direction second hydraulic fluid port, and consequently to main valve control end output sufficient pressure, make the main valve can quick response. When the actuator operates reversely (in return stroke), quick and smooth oil return can be realized.

Drawings

The foregoing and other aspects of the present application will be more fully understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 illustrates a hydraulic circuit of a hydraulic logic valve block according to one possible embodiment of the present application;

FIG. 2 illustrates the hydraulic circuit of the logic valve block of FIG. 1 after the valve position has been switched;

FIG. 3 is a perspective view of one possible configuration of the logic valve block of FIG. 1;

FIGS. 4-6 are front, top, and side views, respectively, of the logic valve block of FIG. 3;

FIGS. 7-9 are cross-sectional views of the logic valve block of FIG. 3 in various positions, respectively;

fig. 10-15 illustrate hydraulic circuits of hydraulic logic valve blocks according to other possible embodiments of the present application.

Detailed Description

The present application relates generally to hydraulic logic valve blocks in which valve elements are mounted in a single valve body in which hydraulic passages are also formed. In this way, the entire hydraulic logic valve block is presented in a single piece for ease of installation and operation.

One possible basic composition of the hydraulic logic valve block of the present application is represented schematically in fig. 1, 2.

It can be seen that the logic valve block has a valve body 1 in the form of a single block of material, and an input port a, a control port b, an output port c, and an oil drain port T are formed on the valve body 1. It will be appreciated that although two ports T are shown on different sides of the valve body 1, in practice only one port T may be provided.

The input port a and the control port b may be connected with a corresponding pressure port and a control port of a pilot valve (not shown) in the hydraulic system, respectively, so that the pilot valve can supply a pilot oil pressure to the input port a and supply a control oil pressure to the control port b. The oil discharge port T is connected to an oil tank (not shown).

The output port c is connected to one control end of a main valve (not shown) in the hydraulic system for supplying the pilot oil pressure from the input port a to the control end of the main valve at two control oil pressures (a first pressure and a second pressure lower than the first pressure) based on different valve positions of the logic valve block. Thus, the hydraulic logic valve block of the present application may be considered a pressure logic valve.

The valve body 1 is provided with a selector valve CV, a first throttle V1, and a second throttle V2.

The directional control valve CV is a two-position three-way valve in this example, and is composed of a valve core, a return spring, an oil port and an oil chamber formed in the valve body 1 and engaged with the valve core, and the like. A plurality of annular undercut grooves are formed on the outer periphery of the valve core, and an internal passage for communicating some of the undercut grooves may be formed inside the valve core. The reversing valve CV is provided with an oil inlet, an oil outlet and an oil drainage port. The construction of the spool and ports of the reversing valve CV is well known in the art and will not be described in detail herein. The valve position of the directional control valve CV is controlled by the oil pressure of the control port b. The directional valve CV has two switchable valve positions, a first valve position being shown in fig. 1 and a second valve position being shown in fig. 2.

In the valve body 1, channels are also formed. These passages are typically formed by punching holes into the valve body 1 from the surface of the valve body 1. For example, a right-angled passage may be formed by two mutually perpendicular surfaces of the valve body 1 punching a hole into the valve body 1, respectively, and finally making the two holes meet. If a certain channel needs to be closed against the surface of the valve body 1, the opening of this channel at the surface of the valve body 1 is closed with a valve plug. This is also well known in the art and will not be described in detail here.

The respective passages formed in the valve body 1 will be described below.

An upstream section of the oil inlet passage L1 is connected to the input port a, and the oil outlet passage L2 is connected between the output port c and the oil outlet of the selector valve CV. In the valve body 1, the downstream section of the oil inlet passage L1 branches into a first branch passage L1a and a second branch passage L1b that are connected in parallel to each other, the first branch passage L1a is connected to the oil outlet passage L2, and the second branch passage L1b is connected to the oil inlet of the selector valve CV.

The drain port of the selector valve CV is connected to an oil discharge passage L4 through an oil discharge passage L3, and the oil discharge passage L4 is connected to the oil discharge port T. Thus, the drain port of the directional control valve CV communicates with the oil discharge port T.

A control passage L5 is connected between the control port b and the control end of the directional valve CV. The reversing valve CV is provided with a return spring on the side opposite to its control end, which is disposed in a spring chamber formed in the valve body 1. The spring chamber is connected to an oil discharge passage L4 through a spring chamber passage L6. Thus, the spring chamber communicates with the oil discharge port T.

A first throttle V1 is disposed in the first branch passage L1a, and a second throttle V2 is disposed in the oil discharge passage L3.

When the pilot valve supplies a control oil pressure to the control port b lower than the valve position switching pressure, the spool is urged by the return spring in the home position (normal position) so that the direction valve CV is in the first valve position, as shown in fig. 1. At the moment, the oil inlet of the valve core is communicated with the oil outlet, and the oil drainage port of the valve core is cut off. Thus, the input port a is connected to the output port c through the first branch passage L1a of the oil inlet passage L1 and the oil outlet passage L2 on the one hand, and is connected to the output port c through the second branch passage L1b of the oil inlet passage L1, the oil inlet and outlet of the spool of the directional valve CV and the oil outlet passage L2 on the other hand. Since the first branch passage L1a is provided with the first flow restriction V1, a certain flow resistance is generated, and the second branch passage L1b is not provided with any flow restriction, so that the flow resistance caused by the flow restriction is not present. Therefore, a large part of the hydraulic oil at the input port a flows into the oil outlet passage L2 through the second branch passage L1b and then flows to the output port c, and a small part of the hydraulic oil flows into the oil outlet passage L2 through the first branch passage L1a and then flows to the output port c. Generally, the flow area between the input port a and the output port c has no influence, the flow resistance is small, the flow is smooth, the pressure drop of the output port c relative to the input port a is small (the pressures of the two are almost equal), and the hydraulic oil of the input port a flows to the output port c completely. Therefore, the hydraulic oil supplied to the input port a by the pilot valve is output from the output port c and supplied to the main valve control end with almost no pressure and flow loss, so that the main valve spool is quickly responsive and moves at the maximum speed, and thus the switching speed of the main valve is fast.

When the pilot valve supplies the control oil pressure to the control port b beyond the valve position switching pressure, the oil pressure of the control port b forces the spool to move to the direction change position against the urging force of the return spring, so that the direction change valve CV is in the second valve position, as shown in fig. 2. At the moment, the oil inlet of the valve core is cut off, and the oil outlet is communicated with the oil drainage port, so that the oil outlet channel L2 is communicated with the oil discharge channel L3. Thus, the input port a is connected to the oil outlet passage L2 through the first branch passage L1a of the oil inlet passage L1, and the oil outlet passage L2 is connected to the output port c on the one hand, and to the oil discharge port T through the oil outlet of the spool of the selector valve CV, and the oil drain port, the oil discharge passage L3 and the oil discharge passage L4 on the other hand. Therefore, the hydraulic oil at the input port a first flows to the oil outlet passage L2 through the first branch passage L1 a. In the first branch passage L1a, the hydraulic oil is throttled by the first throttle V1 to reduce the pressure and flow rate. Next, in the oil outlet passage L2, a part of the hydraulic oil continues to flow to the output port c along the oil outlet passage L2, and the other part of the hydraulic oil flows to the oil discharge port T through the oil outlet and drain port of the spool of the directional control valve CV, the oil discharge passage L3, and the oil discharge passage L4. Since the second throttle V2 is disposed in the oil discharge passage L3 to generate a certain flow resistance, most of the hydraulic oil entering the oil discharge passage L2 flows to the output port c, and a small part flows to the oil discharge port T. Due to the throttling effect of the first throttle V1 and the branching effect of the oil discharge passage L3 with the second throttle V2, the output port c has a certain pressure loss (pressure drop) and flow loss with respect to the input port a. Therefore, the hydraulic oil supplied to the input port a by the pilot valve is output from the output port c and supplied to the main valve control end with a certain pressure and flow loss, so that the main valve spool moves at a speed lower than the maximum speed, and thus there is a certain delay in the switching of the main valve for different work requirements. By designing the throttle area and/or the throttle length of the first throttle V1 and the second throttle V2, the pressure and flow ratio of the output port c relative to the input port a can be adjusted.

The hydraulic logic valve block shown in fig. 1, 2 may be implemented in various suitable designs, for example, one design of the hydraulic logic valve block is illustrated in fig. 3-9.

Referring to fig. 3 to 9, an input port a is formed on the top surface of the valve body 1, and a control port b, an output port c, and an oil discharge port T are formed on the front surface. An oil discharge port T may be further provided at the rear surface of the valve body 1. The spool 4 of the directional valve CV is axially slidably disposed in a valve chamber formed in the valve body 1. The valve chamber opens out from one side of the valve body 1, whereby the opening produced on this side is closed by a screw plug 3. A spring cavity is formed at one axial end of the valve cavity and is used for accommodating a return spring 5 of the reversing valve CV; the other axial end of the valve chamber is formed with a control chamber 2 that communicates with a control port b through a control passage L5 (see fig. 1, 2). The spool position is shown in fig. 7 and 9 with the direction valve in the second position.

Two restrictors (only restrictor V1 is shown in detail in fig. 8 and 9) are arranged in the valve body 1 in the respective channels.

Further, in the valve body 1, the first branch passage L1a opens from the rear surface of the valve body 1, and the opening created on the rear surface of the first branch passage L1a is closed by the plug screw 6.

The specific configuration of the valve spool 4 and the ports in the valve body 1 that engage the valve spool may take forms well known in the art and will not be described here. As for the opening positions of the passages in the valve body 1, they are not described here as long as they can realize the hydraulic circuits shown in fig. 1 and 2.

The hydraulic logic valve block of the present application can also be implemented in other forms, for example, reversing valves other than those described above can be used and the arrangement of the passages and restrictions in the valve block can be modified accordingly.

In fig. 10 is shown another embodiment of the hydraulic logic valve block of the present application, wherein the reversing valve CV is still a two-position, three-way valve, but in contrast to the embodiment shown in fig. 1-9, the second flow restrictor V2 is not provided in the oil drain passage L3, but is contained within the reversing valve CV between the oil outlet and the oil drain of the second valve position. Other aspects of this embodiment are the same as or similar to the embodiment shown in fig. 1 to 9, and substantially the same technical effects can be achieved, and are not described herein again.

Another embodiment of the hydraulic logic valve block of the present application is shown in fig. 11, wherein the reversing valve CV is a two-position four-way valve having an oil inlet, an oil outlet, an oil return, and an oil drain. At first valve position, oil inlet and oil-out intercommunication, oil return opening and draining port are all cuted by the draining port. And in the second valve position, the oil inlet and the oil outlet are cut off, and the oil return port is communicated with the oil drainage port.

The upstream section of the oil inlet passage L1 is connected to the input port a, and the oil outlet passage L2 is connected between the output port c and the oil outlet of the directional valve CV. The downstream section of the oil inlet passage L1 is branched into a first branch passage L1a and a second branch passage L1b which are connected in parallel to each other, the first branch passage L1a is connected to the oil outlet passage L2, and the second branch passage L1b is connected to an oil inlet of the selector valve CV.

The drain port of the change valve CV is connected to the drain passage L4 through the downstream section of the drain passage L3, and the oil return port of the change valve CV is connected to the drain passage L2 through the upstream section of the drain passage L3. A control passage L5 is connected between the control port b and the control end of the directional valve CV. The spring chamber of the return spring of the selector valve CV is connected to the oil discharge passage L4 through a spring chamber passage L6.

A first flow restriction V1 is arranged in the first branch passage L1 a. The second choke V2 is included in the directional valve CV between the oil return and drain ports of the second valve position.

Other aspects of this embodiment are the same as or similar to the embodiment shown in fig. 1-9.

In the present embodiment, when the pilot valve supplies the control oil pressure to the control port b lower than the valve position switching pressure, the selector valve CV is in the first valve position, as shown in fig. 11. At this time, the input port a is connected to the output port c through the first branch passage L1a of the oil inlet passage L1 and the oil outlet passage L2 on the one hand, and is connected to the output port c through the second branch passage L1b of the oil inlet passage L1, the oil inlet and outlet of the spool of the directional valve CV and the oil outlet passage L2 on the other hand. Since the first branch passage L1a is provided with the first flow restriction V1, a certain flow resistance is generated, and the second branch passage L1b is not provided with any flow restriction, so that the flow resistance caused by the flow restriction is not present. Therefore, a large part of the hydraulic oil at the input port a flows into the oil outlet passage L2 through the second branch passage L1b and then flows to the output port c, and a small part of the hydraulic oil flows into the oil outlet passage L2 through the first branch passage L1a and then flows to the output port c. The pressure drop of the output port c with respect to the input port a is small (the pressures are almost equal), and the hydraulic oil of the input port a flows to the output port c in its entirety. Therefore, the hydraulic oil supplied to the input port a by the pilot valve is output from the output port c and supplied to the main valve control port with almost no pressure and flow loss.

When the pilot valve supplies the control oil pressure to the control port b beyond the valve position switching pressure, the direction valve CV is in the second valve position (not shown). At this time, the input port a is connected to the oil outlet passage L2 through the first branch passage L1a of the oil inlet passage L1, and the oil outlet passage L2 is connected to the output port c on the one hand, and to the oil discharge port T through the oil discharge passage L3 (oil return port and oil release port passing through the spool of the direction switching valve CV) and the oil discharge passage L4 on the other hand. Therefore, the hydraulic oil at the input port a first flows to the oil outlet passage L2 through the first branch passage L1 a. In the first branch passage L1a, the hydraulic oil is throttled by the first throttle V1 to reduce the pressure and flow rate. Next, in the oil outlet passage L2, a part of the hydraulic oil continues to flow along the oil outlet passage L2 to the output port c, and the other part of the hydraulic oil flows through the oil drain passage L3 (via the oil return port and the oil drain port of the spool of the selector valve CV) and the oil drain passage L4 to the oil drain port T. Because a second flow restrictor V2 is arranged between the oil return port and the oil drain port of the valve element of the reversing valve CV to generate a certain flow resistance, most of the hydraulic oil entering the oil outlet channel L2 flows to the output port c, and a small part of the hydraulic oil flows to the oil discharge port T. Due to the throttling effect of the first throttle V1 and the branching effect of the oil discharge passage L3 with the second throttle V2, the output port c has a certain pressure loss (pressure drop) and flow loss with respect to the input port a. Therefore, the hydraulic oil supplied to the input port a by the pilot valve is output from the output port c and supplied to the main valve control end with a certain pressure and flow loss.

It can be seen that the present embodiment can produce substantially the same effects as the embodiments shown in fig. 1 to 9.

In fig. 12 is shown another embodiment of the hydraulic logic valve block of the present application, wherein the directional valve CV is also a two-position, four-way valve, but in contrast to the embodiment shown in fig. 11, the second restriction V2 is not contained within the directional valve CV, but is disposed in the oil discharge passage L3 (either in the upstream or downstream sections). Other aspects of this embodiment are the same as or similar to those of the embodiment shown in fig. 11, and substantially the same technical effects can be achieved, which are not described herein again.

Another embodiment of the hydraulic logic valve block of the present application is shown in fig. 13, wherein the directional valves include two directional valves, a first directional valve CV1 and a second directional valve CV 2. The first reversing valve and the second reversing valve are two-position two-way valves which are respectively provided with an oil inlet and an oil outlet, and the valve position switching pressures of the two reversing valves are equal.

At a first valve position of the first reversing valve CV1, the oil inlet is communicated with the oil outlet; at a second position of the first direction valve CV1, both the oil inlet and the oil outlet are blocked.

At a first valve position of the second reversing valve CV2, both the oil inlet and the oil outlet are cut off; at a second valve position of the second direction valve CV2, the oil inlet is communicated with the oil outlet.

An upstream section of the oil inlet passage L1 is connected to the input port a, and the oil outlet passage L2 is connected between the output port c and the oil outlet of the first directional valve CV 1. The downstream section of the oil inlet passage L1 is branched into a first branch passage L1a and a second branch passage L1b which are connected in parallel with each other, the first branch passage L1a is connected to the oil outlet passage L2, and the second branch passage L1b is connected to the oil inlet of the first direction changing valve CV 1. A first throttle V1 is disposed in the first branch passage L1 a.

An oil discharge passage L3 passes through the oil inlet and the oil outlet of the second reversing valve CV2 and is connected between the oil outlet passage L2 and the oil discharge passage L4. A second throttle V2 is disposed in the oil discharge passage L3. The second choke V2 may be located upstream of the second direction valve CV2 in the oil discharge passage L3 or downstream of the second direction valve CV 2.

A control passage L5 leads from control port b to the respective control ends of the first and second directional valves CV1 and CV 2.

The spring chamber passage L6 of the first direction valve CV1 is connected to the oil discharge passage L4. The spring chamber passage L6 of the second direction valve CV2 is connected to the oil discharge passage L3 or directly to the oil discharge passage L4.

Other aspects of this embodiment are the same as or similar to the embodiment shown in fig. 1-9.

In the present embodiment, when the pilot valve supplies the control oil pressure to the control port b lower than the valve position switching pressure, both the first direction valve CV1 and the second direction valve CV2 are in the first valve position, as shown in fig. 13. At this time, the input port a is connected to the output port c through the first branch passage L1a of the oil inlet passage L1 and the oil outlet passage L2 on the one hand, and is connected to the output port c through the second branch passage L1b of the oil inlet passage L1, the oil inlet and outlet of the first directional valve CV1 and the oil outlet passage L2 on the other hand. Since the first branch passage L1a is provided with the first flow restriction V1, a certain flow resistance is generated, and the second branch passage L1b is not provided with any flow restriction, so that the flow resistance caused by the flow restriction is not present. Therefore, most of the hydraulic oil at the input port a flows through the second branch passage L1b, the first directional control valve CV1, the oil outlet passage L2, and then flows to the output port c, and a small part of the hydraulic oil flows through the first branch passage L1a, flows into the oil outlet passage L2, and then flows to the output port c. In general, the flow resistance between the input port a and the output port c is small, the pressure drop of the output port c with respect to the input port a is small, and the hydraulic oil of the input port a flows to the output port c in its entirety. Therefore, the hydraulic oil supplied to the input port a by the pilot valve is output from the output port c and supplied to the main valve control port with almost no pressure and flow loss.

When the pilot valve supplies control oil pressure to the control port b in excess of the valve position switching pressure, both the first direction valve CV1 and the second direction valve CV2 are in the second valve position (not shown). At this time, the input port a is connected to the oil outlet passage L2 through the first branch passage L1a of the oil inlet passage L1, and the oil outlet passage L2 is connected to the output port c on the one hand, and to the oil discharge port T through the oil discharge passage L3 (passing through the second throttle V2) and the oil discharge passage L4 on the other hand. Therefore, the hydraulic oil at the input port a first flows to the oil outlet passage L2 through the first branch passage L1 a. In the first branch passage L1a, the hydraulic oil is throttled by the first throttle V1 to reduce the pressure and flow rate. Next, in the oil outlet passage L2, a part of the hydraulic oil continues to flow along the oil outlet passage L2 to the output port c, and another part flows to the oil discharge port T through the oil discharge passage L3 (passing through the second restrictor V2), the oil discharge passage L4, and the oil discharge passage L4. Since the second throttle V2 is disposed in the oil discharge passage L3 to generate a certain flow resistance, most of the hydraulic oil entering the oil discharge passage L2 flows to the output port c, and a small part of the hydraulic oil flows to the oil discharge port T. Due to the throttling effect of the first throttle V1 and the branching effect of the oil discharge passage L3 with the second throttle V2, the output port c has a certain pressure loss (pressure drop) and flow loss with respect to the input port a. Therefore, the hydraulic oil supplied to the input port a by the pilot valve is output from the output port c and supplied to the main valve control end with a certain pressure and flow loss.

It can be seen that the present embodiment can produce substantially the same effects as the embodiments shown in fig. 1 to 9.

It will be appreciated that in this embodiment, the second throttle V2 may also be included in the second direction valve CV2 between the oil outlet and the oil drain of its second valve position, rather than being disposed in the oil drain L3 as in fig. 13.

Another embodiment of the hydraulic logic valve block of the present application is shown in fig. 14, wherein the reversing valve CV is a two-position, four-way valve, but the spool of the two-position, four-way valve includes four sub-spools combined together, each sub-spool having a respective oil inlet and outlet. An oil inlet of the first sub valve core is communicated with an oil outlet; the oil inlet and the oil outlet of the second sub valve core are both cut off; the oil inlet and the oil outlet of the third sub-valve core are both cut off; and the oil inlet of the fourth sub valve core is communicated with the oil outlet. The valve position of the directional valve CV is controlled by a control passage L5 connected to the control port b. A first throttle V1 is disposed in the first branch passage L1a of the oil inlet passage L1, and a second throttle V2 is disposed in the oil discharge passage L3 (in an upstream section or a downstream section).

In the first valve position, as shown in fig. 14, the second branch passage L1b of the oil inlet passage L1 is connected to the oil inlet of the first sub-valve spool, the oil outlet passage L2 is connected to the oil outlet of the first sub-valve spool, the downstream section of the oil discharge passage L3 is connected between the oil inlet of the third sub-valve spool and the oil discharge passage L4, and the upstream section of the oil discharge passage L3 is connected between the oil outlet of the third sub-valve spool and the oil outlet passage L2.

In a second valve position (not shown), a second branch passage L1b of the oil inlet passage L1 is connected to the oil inlet of the second sub-valve spool, the oil outlet passage L2 is connected to the oil outlet of the second sub-valve spool, a downstream section of the oil discharge passage L3 is connected between the oil inlet of the fourth sub-valve spool and the oil discharge passage L4, and an upstream section of the oil discharge passage L3 is connected between the oil outlet of the fourth sub-valve spool and the oil outlet passage L2.

Other aspects of this embodiment are the same as or similar to those of the embodiment shown in fig. 12, and substantially the same technical effects can be achieved, which are not described herein again.

Another embodiment of the hydraulic logic valve block of the present application is shown in fig. 15, wherein, but in contrast to the embodiment shown in fig. 14, the second flow restrictor V2 is not disposed in the oil dump passage L3, but is contained within the fourth sub-spool of the reversing valve CV, between the oil inlet and outlet ports of the fourth sub-spool. Other aspects of this embodiment are the same as or similar to those of the embodiments shown in fig. 11 and 14, and substantially the same technical effects can be achieved, which are not described herein again.

In summary, the hydraulic logic valve block of the present application can enable the input port a to output at the output port c at two pressures and flows based on the pressure level of the control port b. In the first position of the directional control valve, the feed path from the inlet port a to the outlet port c is free of a throttle, so that hydraulic oil with little pressure and flow losses can be discharged, i.e. at a higher first pressure. In the second position of the directional control valve, there is a first restriction in the delivery path from the input port a to the output port c, and there is also a branch path for the hydraulic oil to branch from the delivery path to the drain port T, in which branch path there is a second restriction, so that the output port c outputs the hydraulic oil with a proportional pressure drop (i.e., with a second pressure lower than the first pressure) and flow loss. Therefore, the hydraulic logic valve block can output two levels of hydraulic pressure to the main valve, so that the main valve executes different operations. In other words, the hydraulic logic valve block has a hydraulic logic control function that outputs a hydraulic pressure as a control signal to the main valve based on the hydraulic pressure level received by the control port b, thereby controlling the operation of the main valve. In the first position of the directional valve, the hydraulic oil of the input port a is output from the output port c with almost no pressure and flow loss and is supplied to the main valve control end, so that the main valve spool moves at the maximum speed, and thus the response speed of the main valve is fast.

Although the oil pressure of the input port a and the control port b of the hydraulic logic valve block is from the pilot valve and the oil pressure of the output port c is transmitted to the control end of the main valve in the above-described embodiments, the oil pressure of the input port a and the control port b may be from other hydraulic components (from the same component or different components), and the oil pressure of the output port c may be transmitted as a control signal to other controlled hydraulic components.

It should be noted that the throttle device described in the present application may be a throttle valve, a throttle hole, or other throttle element. When a flow restrictor is included in the reversing valve, the flow restrictor is typically provided in the valve spool in the form of a plug-in damper, as is well known in the art.

Note that, when the hydraulic actuator controlled by the main valve is operating in the forward direction (course), the input port a of the hydraulic logic valve block is used as an oil inlet, and the output port c is used as an oil outlet. When the hydraulic actuator controlled by the main valve operates reversely (in a return stroke), the output port c of the hydraulic logic valve block is used as an oil inlet, the oil inlet is unlimited, the input port a is used as an oil return port, and the control port b has no pressure. Therefore, in a more general sense, the input port a may be referred to as a first port a, and the output port c may be referred to as a second port c. Accordingly, the oil inlet passage L1 may be referred to as the first oil passage L1, and the oil outlet passage L2 may be referred to as the second oil passage L2.

No matter the hydraulic actuator operates in the forward direction or the reverse direction, hydraulic oil can flow between the first oil port and the second oil port quickly and smoothly.

Although the present application has been described herein with reference to particular embodiments, the scope of the present application is not intended to be limited to the details shown. Various modifications may be made to these details without departing from the underlying principles of the application.

Claims (10)

1. A hydraulic logic valve block comprising:

the valve body (1) is provided with a first oil port (a), a control port (b), a second oil port (c) and an oil unloading port (T); and

a reversing valve (CV) arranged in the valve body, a first throttle (V1), a second throttle (V2);

it is characterized in that the hydraulic logic valve block also comprises:

a first oil passage (L1) connected to the first oil port (a) and branched into a first branch passage (L1a) and a second branch passage (L1b), the first throttle (V1) being provided in the first branch passage (L1 a);

a second oil passage (L2) connecting the second oil port (c) and the first branch passage (L1 a);

an oil discharge passage (L3) connected to the oil discharge port (T);

a control passage (L5) connected between the control port (b) and the control end of the directional valve (CV) for controlling the valve position of the directional valve (CV);

wherein the second branch passage (L1b) is communicated with or disconnected from the second oil passage (L2) through the Change Valve (CV);

the oil discharge passage (L3) is communicated with or disconnected from the second oil passage (L2) through the reversing valve (CV);

the second restrictor (V2) is provided in the oil discharge passage (L3) or in a change valve internal passage that establishes communication between the oil discharge passage (L3) and the second oil passage (L2);

the Change Valve (CV) connects the second branch passage (L1b) and the second oil passage (L2) and disconnects the oil discharge passage (L3) and the second oil passage (L2) at the first valve position, and disconnects the second branch passage (L1b) and the second oil passage (L2) and connects the oil discharge passage (L3) and the second oil passage (L2) at the second valve position.

2. The hydraulic logic valve block as recited in claim 1, characterized in that the directional Control Valve (CV) is a two-position three-way valve having an oil inlet, an oil outlet, and an oil drain, the second branch passage (L1b) is connected to the oil inlet, the second oil passage (L2) is connected to the oil outlet, and the oil drain passage (L3) is connected to the oil drain; at the first valve position, the oil inlet is communicated with the oil outlet, and the oil drain port is cut off; and at the second valve position, the oil inlet is cut off, and the oil outlet is communicated with the oil drainage port.

3. The hydraulic logic valve block as recited in claim 2, characterized in that the second flow restrictor (V2) is disposed within the reversing valve CV between the oil outlet and the drain port below the second valve position.

4. The hydraulic logic valve block as claimed in claim 1, wherein the directional Control Valve (CV) is a two-position four-way valve having an oil inlet, an oil outlet, an oil return port, and an oil drain port, the second branch passage (L1b) is connected to the oil inlet, the second oil passage (L2) is connected to the oil outlet, an upstream section of the oil drain passage (L3) is connected between the oil return port and the second oil passage (L2), and a downstream section of the oil drain passage (L3) is connected between the oil drain port and the oil drain port (T); at first valve position, oil inlet and oil-out intercommunication, oil return opening and draining port are all cuted by the draining port, and at second valve position, oil inlet and oil-out are all cuted, oil return opening and draining port intercommunication.

5. The hydraulic logic valve block as claimed in claim 4, wherein the second restrictor (V2) is provided in an upstream section or a downstream section of the oil discharge passage (L3); or

The second throttle (V2) is disposed in the directional control valve CV between the oil return port and the oil release port below the second valve position.

6. The hydraulic logic valve block as recited in claim 1, characterized in that the directional Control Valve (CV) comprises a first directional control valve (CV1) and a second directional control valve (CV2), both of which are two-position, two-way valves having an oil inlet and an oil outlet, respectively;

the second branch channel (L1b) is connected with an oil inlet of the first reversing valve (CV1), the second oil duct (L2) is connected with an oil outlet of the first reversing valve (CV1), an upstream section of the oil discharging channel (L3) is connected between an oil outlet of the second reversing valve (CV2) and the second oil duct (L2), and a downstream section of the oil discharging channel (L3) is connected between an oil inlet of the second reversing valve (CV2) and the oil discharging port (T);

in the first valve position, the oil inlet and the oil outlet of the first reversing valve (CV1) are communicated, and the oil inlet and the oil outlet of the second reversing valve (CV2) are both cut off; in the second valve position, the oil inlet and the oil outlet of the first reversing valve (CV1) are cut off, and the oil inlet and the oil outlet of the second reversing valve (CV2) are communicated.

7. The hydraulic logic valve block as claimed in claim 6, wherein the second restrictor (V2) is provided in an upstream section or a downstream section of the oil drain passage (L3); or

The second throttling device (V2) is arranged between an oil inlet and an oil outlet below the second valve position in the second reversing valve (CV 2).

8. The hydraulic logic valve block as recited in claim 1, wherein the directional Control Valve (CV) is a two-position, four-way valve having a spool comprising four sub-spools combined together, each sub-spool having a respective inlet and outlet;

an oil inlet and an oil outlet of the first sub valve core are communicated, an oil inlet and an oil outlet of the second sub valve core are cut off, an oil inlet and an oil outlet of the third sub valve core are cut off, and an oil inlet of the fourth sub valve core is communicated with the oil outlet;

in the first valve position, a second branch channel (L1b) is connected to an oil inlet of the first sub valve core, a second oil channel (L2) is connected to an oil outlet of the first sub valve core, an upstream section of an oil unloading channel (L3) is connected between an oil outlet of the third sub valve core and the second oil channel (L2), and a downstream section of the oil unloading channel (L3) is connected between an oil inlet of the third sub valve core and the oil unloading port (T);

at the second valve position, a second branch channel (L1b) is connected to the oil inlet of the second sub valve core, a second oil channel (L2) is connected to the oil outlet of the second sub valve core, the upstream section of an oil discharge channel (L3) is connected between the oil outlet of the fourth sub valve core and the second oil channel (L2), and the downstream section of the oil discharge channel (L3) is connected between the oil inlet of the fourth sub valve core and the oil discharge channel (L4).

9. The hydraulic logic valve block as claimed in claim 8, wherein the second restrictor (V2) is provided in an upstream section or a downstream section of the oil drain passage (L3); or

The second throttling device (V2) is arranged between the oil inlet and the oil outlet of the fourth sub valve core in the fourth sub valve core.

10. The hydraulic logic valve block as recited in any of claims 1-9, characterized in that the flow resistance of the first flow restrictor (V1) and the second flow restrictor (V2) are adjustable, thereby adjusting the output pressure of the second port (c) below the first valve position and the second valve position.

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