Back pressure valve

Abstract

The invention provides a back pressure valve, and belongs to the technical field of valves. The back pressure valve comprises a pressure reducing valve unit and a back pressure valve unit, the pressure reducing valve unit comprises a first valve body and a first valve element assembly, and a first oil inlet, an oil outlet and a feedback oil port are formed in the first valve body; the first valve element assembly is movably located in the first valve body, the back pressure valve unit comprises a second valve body and a second valve element assembly, a second oil inlet, a throttling oil port and an unloading oil port are formed in the second valve body at intervals, the second oil inlet is communicated with the oil outlet, and the second oil outlet is communicated with the second valve element assembly. The throttling oil port is respectively communicated with the second oil inlet and the unloading oil port, and the flow area of the unloading oil port is larger than that of the throttling oil port; the second valve element assembly is movably located in the second valve body. The invention can reduce vibration and noise.

Description

Technical Field

[0001] The present invention belongs to the technical field of valve components, and in particular relates to a back pressure valve. Background Art

[0002] Back pressure valve is an important instrument in industrial automation process control, used to prevent liquid from flowing or siphoning under gravity. Back pressure valve is usually installed at the pump outlet, which can not only stabilize the output flow of the pump, but also be used as a safety valve when the requirements are not too strict.

[0003] In the related art, the back-pressure valve includes a valve body, a diaphragm and a spring. The valve body has an oil inlet and a throttle port. The diaphragm and the spring are both located inside the valve body. The diaphragm is located at the oil inlet, and the diaphragm is against one end of the spring. The hydraulic oil enters the safety valve through the oil inlet and contacts the diaphragm. The throttle port is used to discharge the hydraulic oil in the back-pressure valve. When the hydraulic oil pressure at the oil inlet is greater than the elastic force of the spring, the diaphragm is lifted up by the hydraulic oil, the oil inlet and the throttle port form a passage, the back-pressure valve opens, and the pressure is limited. Conversely, when the hydraulic oil pressure at the oil inlet cannot lift up the diaphragm, the oil inlet and the throttle port are disconnected, and the back-pressure valve holds the pressure until the hydraulic oil pressure at the oil inlet reaches the elastic force of the spring (that is, the rated pressure).

[0004] However, in the above back-pressure valve, since the back-pressure valve can only be released through the throttle port when the pressure is released, when the pump outlet pressure and flow rate gradually increase, the pressure loss generated at the throttle port when the back-pressure valve is released will be larger, thereby causing greater vibration and noise, making the back-pressure valve work poorly and affecting the pump outlet pressure. Summary of the invention

[0005] The embodiment of the present disclosure provides a back pressure valve that can reduce noise and vibration. The technical solution is as follows:

[0006] The embodiment of the present disclosure provides a back-pressure valve, wherein the back-pressure valve comprises a pressure reducing valve unit and a back-pressure valve unit, wherein the pressure reducing valve unit comprises a first valve body and a first valve core assembly, wherein the first valve body has a first oil inlet, an oil outlet and a feedback oil port, wherein the oil outlet is connected to the first oil inlet and the feedback oil port respectively; the first valve core assembly is movably located in the first valve body, and the first valve core assembly is configured to: connect the first oil inlet and the oil outlet when the pressure at the feedback oil port is not greater than a first threshold value, and control the connecting area between the first oil inlet and the oil outlet when the pressure at the feedback oil port is greater than the first threshold value, wherein the connecting area decreases as the pressure at the feedback oil port increases; the back-pressure valve unit comprises a second valve body and a a second valve core assembly, wherein the second valve body is connected to the first valve body, the second valve body having a second oil inlet, a throttling oil port and a unloading oil port, the second oil inlet is connected to the oil outlet, the two ends of the throttling oil port are respectively connected to the second oil inlet and the unloading oil port, the flow area of ​​the unloading oil port is larger than the flow area of ​​the throttling oil port, and the unloading oil port is connected to the oil tank; the second valve core assembly is movably located in the second valve body, and the second valve core assembly is configured to: when the pressure at the second oil inlet is larger than a second threshold value, connect the second oil inlet and the unloading oil port, and when the pressure at the second oil inlet is not larger than the second threshold value, isolate the second oil inlet from the unloading oil port, and the second threshold value is larger than the first threshold value.

[0007] In another embodiment of the present disclosure, the first valve core assembly includes a first valve core body, which is movably located in the first valve body, and one end of the first valve core body faces the feedback oil port; the first valve core body includes a valve stem and a first outer flange arranged on the middle outer wall of the valve stem, the outer wall of the first outer flange is in sliding contact with the inner wall of the first valve body, the first outer flange is located between the first oil inlet and the oil outlet, when the pressure at the feedback oil port is not greater than a first threshold value, a flow channel connecting the first oil inlet and the oil outlet is formed between the first outer flange and the inner wall of the first valve body, and when the pressure at the feedback oil port is greater than the first threshold value, the flow area of ​​the flow channel gradually decreases.

[0008] In another embodiment of the present disclosure, the outer wall of one end of the first outer flange facing the oil outlet has a plurality of notches, the plurality of notches are arranged at intervals along the circumference of the first outer flange, and each of the plurality of notches extends from the end surface of the first outer flange facing the oil outlet to the outer wall of the first outer flange.

[0009] In another implementation of the present disclosure, the first valve core assembly also includes a first spring seat and a first elastic member, the first spring seat is located at one end of the first valve core body away from the feedback oil port, and is connected to one end of the first valve core body; the first elastic member is sleeved on the other end of the first spring seat away from the first valve core body, and the two ends of the first elastic member are respectively against the first spring seat and the inner wall of the first valve body.

[0010] In another implementation of the present disclosure, the first valve body includes a first end plate, a second end plate and a valve block, the first end plate and the second end plate are respectively located on opposite sides of the valve block, and the first end plate and the second end plate are respectively connected to the valve block; a plate surface of the first end plate facing the second end plate has a first protrusion, the first protrusion is located in the valve block and is used to contact with one end of the first valve core body; a plate surface of the second end plate facing the first end plate has a second protrusion, the second protrusion is inserted in the first elastic member, and the second end plate is abutted against one end of the first elastic member.

[0011] In another embodiment of the present disclosure, a feedback oil storage chamber is provided inside the first protrusion, and the feedback oil storage chamber is arranged along the length direction of the first protrusion and extends to an end surface of the first protrusion facing the first valve core assembly; the side wall of the first protrusion has a plurality of flow holes, and the plurality of flow holes are arranged at intervals along the circumference of the first protrusion, and each of the plurality of flow holes is respectively connected to the feedback oil storage chamber and the feedback oil port.

[0012] In another embodiment of the present disclosure, the second valve body includes a valve sleeve and a throttle sleeve; the valve sleeve is located at the oil outlet of the first valve body, and one end of the valve sleeve is connected to the side wall of the first valve body; the throttle sleeve is located inside the end of the valve sleeve facing the first valve body, and the throttle sleeve is connected to the valve sleeve; the throttle sleeve has an inner flange in the inner wall of the end away from the first valve body, the throttle oil port passes through the opposite end surfaces of the inner flange along the axis of the inner flange, and the inner hole of the inner flange defines the second oil inlet.

[0013] In another implementation of the present disclosure, the unloading oil port is located in the middle of the valve sleeve; the second valve core assembly includes a second valve core body, the second valve core body is movably located in the valve sleeve, and is located at an end of the throttling sleeve away from the first valve body, when the pressure at the second oil inlet port is greater than a second threshold value, the second valve core body is spaced from the throttling sleeve, and a connecting channel connecting the unloading oil port and the second oil inlet port is formed between the outer wall of the second valve core body and the valve sleeve, and when the pressure at the second oil inlet port is not greater than the second threshold value, the second valve core body blocks the inner hole of the inner flange.

[0014] In another implementation of the present disclosure, the outer wall of the second valve core body at one end facing the throttling sleeve has a first sealing bevel; the inner wall of the throttling sleeve at one end facing the second valve core body has a second sealing bevel, and when the pressure at the second oil inlet is not greater than a second threshold value, the first sealing bevel and the second sealing bevel fit together.

[0015] In another implementation of the present disclosure, the second valve core assembly also includes a second elastic member, the second elastic member is located in the valve sleeve, and the second elastic member is located on the side of the second valve core body away from the throttling sleeve, and the two ends of the second elastic member are respectively against the valve sleeve and the second valve core body.

[0016] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0017] When the back pressure valve provided in the embodiment of the present disclosure is connected to the pump outlet. The pump outlet is connected to the first oil inlet. The hydraulic oil flowing out of the pump outlet enters the first valve body through the first oil inlet. Since the hydraulic oil has not yet entered the oil outlet, the pressure at the feedback oil port is zero. At this time, the first valve core assembly can connect the first oil inlet and the oil outlet, and the hydraulic oil enters the oil outlet. As the oil pressure at the pump outlet continues to increase, the oil pressure at the oil outlet also continues to increase. Since the feedback oil port is connected to the oil outlet, the oil pressure at the feedback oil port also continues to increase. When the pressure at the feedback oil port is greater than the first threshold value, as the pressure at the feedback oil port continues to increase, the connecting area between the first oil inlet and the oil outlet gradually decreases, so the oil pressure at the oil outlet gradually decreases, achieving pressure reduction.

[0018] Part of the hydraulic oil entering the oil outlet enters the feedback oil port to adjust the communication area between the first oil inlet and the oil outlet, and the other part of the hydraulic oil enters the second valve body through the second oil inlet. Since the throttling oil port is connected with the second oil inlet and the unloading oil port respectively, the hydraulic oil entering the second oil inlet is throttled by the throttling oil port and then discharged through the unloading oil port. As the oil pressure at the oil outlet gradually increases, the pressure at the second oil inlet gradually increases. When the pressure at the second oil inlet is greater than the second threshold, the second oil inlet is connected with the unloading oil port, so the hydraulic oil in the second oil inlet is directly discharged through the unloading oil port to achieve pressure relief. Since the flow area of ​​the unloading oil port is larger than the flow area of ​​the throttling oil port, the pressure drop of the oil in and out of the back pressure valve can be reduced through the unloading oil port, thereby reducing the vibration and noise of the back pressure valve and achieving the purpose of noise reduction and vibration reduction.

[0019] That is to say, when the pump outlet pressure is relatively low, the back pressure valve provided in the embodiment of the present disclosure directly throttles and discharges the hydraulic oil through the throttling oil port, so that the hydraulic oil pressure after discharge is relatively low. As the pump outlet pressure gradually increases, the hydraulic oil is first decompressed through the oil outlet and then enters the throttling oil port before being discharged, so that the hydraulic oil pressure after discharge is still not too high. When the pump outlet pressure is very high, until the pressure at the second oil inlet is greater than the second threshold, the hydraulic oil is not only discharged through the throttling oil port, but also directly unloaded through the unloading oil port, limiting the pump outlet pressure, so that the pump outlet pressure is always maintained within a relatively stable range, thereby achieving the functions of voltage stabilization and noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a structural schematic diagram of a back pressure valve provided by an embodiment of the present disclosure;

[0022] Figure 2 is a three-dimensional schematic diagram of a first valve core assembly;

[0023] Figure 3 for Figure 1 A schematic diagram of the structure of the first valve core body;

[0024] Figure 4 for Figure 1 An exploded schematic diagram of the first valve body;

[0025] Figure 5 for Figure 1 A schematic diagram of the structure of the middle throttle valve unit;

[0026] Figure 6 It is a structural schematic diagram of the throttling sleeve;

[0027] Figure 7 is a structural schematic diagram of the second valve core body;

[0028] Figure 8 It is a schematic diagram of the structure of the sleeve body.

[0029] The symbols in the figure mean the following:

[0030] 1. Pressure reducing valve unit; 11. First valve body; 1101. First oil inlet; 1102. Oil outlet; 1103. Feedback oil port; 111. First end plate; 1111. First protrusion; 1112. Feedback oil storage cavity; 1113. Flow hole; 112. Second end plate; 1121. Second protrusion; 113. Valve block; 1130. Strip cavity; 1131. Mounting hole; 1132. Oil passage; 12. First valve core assembly; 121. First valve core body; 1211. Valve stem; 1212. First outer flange; 1213. Second outer flange; 1214. Third outer flange; 1104. Flow passage; 1105. Notch; 122. Spring seat; 123. First elastic member;

[0031] 2. Back-pressure valve unit; 21. Second valve body; 211. Valve sleeve; 2111. Sleeve body; 2112. Valve cover; 2113. Spring seat; 2114. Screw; 2115. Nut; 212. Throttle sleeve; 2121. Inner flange; 2101. Second oil inlet; 2102. Throttle oil port; 2103. Unloading oil port; 22. Second valve core assembly; 221. Second valve core body; 2211. Reduction section; 2212. Expansion section; 2210. First sealing bevel; 2120. Second sealing bevel; 223. Second elastic member; 201. First positioning stop; 202. Second positioning stop. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0033] The present disclosure provides a back pressure valve. Figure 1 As shown, the back-pressure valve includes a pressure reducing valve unit 1 and a back-pressure valve unit 2. The pressure reducing valve unit 1 includes a first valve body 11 and a first valve core assembly 12. The first valve body 11 has a first oil inlet 1101, an oil outlet 1102 and a feedback oil port 1103. The oil outlet 1102 is connected to the first oil inlet 1101 and the feedback oil port 1103 respectively.

[0034] The first valve core assembly 12 is movably located in the first valve body 11, and the first valve core assembly 12 is configured to: connect the first oil inlet 1101 and the oil outlet 1102 when the pressure at the feedback oil port 1103 is not greater than the first threshold value, and control the connecting area between the first oil inlet 1101 and the oil outlet 1102 when the pressure at the feedback oil port 1103 is greater than the first threshold value, and the connecting area decreases as the pressure at the feedback oil port 1103 increases.

[0035] The back pressure valve unit 2 includes a second valve body 21 and a second valve core assembly 22, and the second valve body 21 is connected to the first valve body 11. The second valve body 21 has a second oil inlet 2101, a throttling oil port 2102 and an unloading oil port 2103 arranged at intervals, the second oil inlet 2101 is connected to the oil outlet 1102, the throttling oil port 2102 is respectively connected to the second oil inlet 2101 and the unloading oil port 2103, and the flow area of ​​the unloading oil port 2103 is larger than the flow area of ​​the throttling oil port 2102. The unloading oil port 2103 is connected to the oil tank to recover the oil into the oil tank.

[0036] The second valve core assembly 22 is movably located in the second valve body 21, and the second valve core assembly 22 is configured to: when the pressure at the second oil inlet 2101 is greater than the second threshold, connect the second oil inlet 2101 with the unloading oil port 2103, and when the pressure at the second oil inlet 2101 is not greater than the second threshold, isolate the second oil inlet 2101 from the throttling oil port 2102. The second threshold is greater than the first threshold.

[0037] When the back-pressure valve provided by the embodiment of the present disclosure is used, the back-pressure valve can be connected to the pump outlet, for example. The pump outlet is connected to the first oil inlet 1101. The hydraulic oil pumped out of the pump outlet enters the first valve body 11 through the first oil inlet 1101. Since the first valve core assembly 12 is movably located in the first valve body 11, and since the hydraulic oil has not yet entered the oil outlet 1102, the pressure at the feedback oil port 1103 is zero. The first valve core assembly 12 enables the first oil inlet 1101 and the oil outlet 1102 to be connected, and the hydraulic oil enters the oil outlet 1102. As the oil pressure at the pump outlet continues to increase, the oil pressure at the oil outlet 1102 also continues to increase. Since the feedback oil port 1103 is connected to the oil outlet 1102, the oil pressure at the feedback oil port 1103 also continues to increase. When the pressure at the feedback oil port 1103 is greater than the first threshold, as the pressure at the feedback oil port 1103 continues to increase, the connection area between the first oil inlet 1101 and the oil outlet 1102 gradually decreases, so the oil pressure at the oil outlet 1102 gradually decreases.

[0038] Since the second oil inlet 2101 is connected to the oil outlet 1102, part of the hydraulic oil entering the oil outlet 1102 enters the feedback oil port 1103 to adjust the communication area between the first oil inlet 1101 and the oil outlet 1102, and the other part of the hydraulic oil enters the second valve body 21 through the second oil inlet 2101. Since the throttling oil port 2102 is respectively connected to the second oil inlet 2101 and the unloading oil port 2103, the hydraulic oil entering the second oil inlet 2101 is throttled by the throttling oil port 2102 and discharged through the unloading oil port 2103. As the oil pressure at the oil outlet 1102 gradually increases, the pressure at the second oil inlet 2101 gradually increases. When the pressure at the second oil inlet 2101 is greater than the second threshold, the second oil inlet 2101 is connected to the unloading oil port 2103, so the hydraulic oil in the second oil inlet 2101 is directly discharged through the unloading oil port 2103 to achieve pressure relief. Since the flow area of ​​the unloading oil port 2103 is larger than the flow area of ​​the throttling oil port 2102, the pressure drop can be reduced through the unloading oil port 2103, thereby reducing the pressure at the pump outlet and reducing energy loss.

[0039] That is to say, when the pump outlet pressure is relatively low, the back pressure valve provided in the embodiment of the present disclosure directly throttles and discharges through the throttling oil port 2102, so that the hydraulic oil pressure after discharge is relatively low. As the pump outlet pressure gradually increases, the hydraulic oil is first decompressed through the oil outlet 1102 and then enters the throttling oil port 2102 and is discharged, so that the hydraulic oil pressure after discharge is still not too high. When the pump outlet pressure is very high, until the pressure at the second oil inlet 2101 is greater than the second threshold, the hydraulic oil is not only discharged through the throttling oil port 2102, but also directly unloaded through the unloading oil port 2103, limiting the pump outlet pressure, so that the pump outlet pressure is always maintained within a relatively stable range, thereby achieving the functions of voltage stabilization and noise reduction.

[0040] Optionally, the first valve core assembly 12 includes a first valve core body 121 , and the first valve core body 121 is movably located in the first valve body 11 along its own length direction.

[0041] Figure 2 is a three-dimensional schematic diagram of the first valve core component, combined with Figure 2 The first valve core body 121 includes a valve stem 1211 and a first outer flange 1212 arranged at the middle outer wall of the valve stem 1211 , and the outer wall of the first outer flange 1212 is in sliding contact with the inner wall of the first valve body 11 .

[0042] Combination Figure 1The first outer flange 1212 is located between the first oil inlet 1101 and the oil outlet 1102. When the pressure at the feedback oil port 1103 is not greater than the first threshold value, a flow channel 1104 connecting the first oil inlet 1101 and the oil outlet 1102 is formed between the first outer flange 1212 and the inner wall of the first valve body 11. When the pressure at the feedback oil port 1103 is greater than the first threshold value, the flow area of ​​the flow channel 1104 gradually decreases.

[0043] In the above implementation, the first valve core body 121 is configured as the above structure, and the first outer flange 1212 can follow the movement of the valve stem 1211 to control whether the first oil inlet 1101 and the oil outlet 1102 are connected.

[0044] That is to say, by arranging the first outer flange 1212 outside the first valve core body 121 , the movement of the first valve core body 121 can be controlled to control whether the first oil inlet 1101 and the oil outlet 1102 are connected.

[0045] See again Figure 2 Optionally, the outer wall of the first outer flange 1212 at one end facing the oil outlet 1102 has a plurality of notches 1105, and the plurality of notches 1105 are arranged at intervals along the circumference of the first outer flange 1212. Each notch 1105 extends from the outer wall of the first outer flange 1212 at one end facing the oil outlet 1102.

[0046] In the above implementation, the notch 1105 can form a flow channel 1104 between the first outer flange 1212 and the inner wall of the first valve body 11 , thereby facilitating the hydraulic oil to flow from the first oil inlet 1101 to the oil outlet 1102 .

[0047] Exemplarily, the axis from the bottom wall of each notch 1105 to the valve stem 1211 gradually decreases along the direction from the feedback oil port 1103 to the oil outlet 1102 .

[0048] This can further limit the flow area of ​​the flow channel 1104 formed between the first outer flange 1212 and the inner wall of the first valve body 11, so that the flow area will not be too large, thereby throttling and limiting the pressure of the hydraulic oil entering the oil outlet 1102.

[0049] Continue to see Figure 2Optionally, the first valve core body 121 further includes a second outer flange 1213 and a third outer flange 1214, which are respectively located outside the two ends of the valve stem 1211 and are both connected to the outer wall of the valve stem 1211. The second outer flange 1213 is located between the feedback oil port 1103 and the first outer flange 1212, and the third outer flange 1214 is located on the side of the oil outlet 1102 away from the first outer flange 1212. The second outer flange 1213 and the third outer flange 1214 are both in sliding contact with the inner wall of the first valve body 11. In the initial state, the second outer flange 1213 is in contact with one end of the first valve body 11 in the length direction, and the third outer flange 1214 is spaced from the other end of the first valve body 11 in the length direction.

[0050] In the above implementation, the arrangement of the second outer flange 1213 and the third outer flange 1214 can further limit the movement of the first valve core body 121, so that when the first valve core body 121 moves relative to the first valve body 11, it can only move along the path inside the first valve body 11 and will not move at will.

[0051] Figure 3 for Figure 1 The structural diagram of the first valve core body, combined with Figure 3 In this embodiment, for ease of arrangement, the outer diameters of the first outer flange 1212, the second outer flange 1213 and the third outer flange 1214 are the same.

[0052] See again Figure 1 Optionally, the first valve core assembly 12 further includes a first spring seat 122 and a first elastic member 123. The first spring seat 122 is located at one end of the first valve core body 121 away from the feedback oil port 1103 and is connected to one end of the first valve core body 121. The outer diameter of the first spring seat 122 at one end facing the first valve core body 121 is greater than the outer diameter of the other end.

[0053] The first elastic member 123 is sleeved on the other end of the first spring seat 122 away from the first valve core body 121 , and two ends of the first elastic member 123 abut against the first spring seat 122 and the inner wall of the first valve body 11 respectively.

[0054] In the above implementation, the first spring seat 122 is used to connect with the first valve core body 121. At the same time, the outer diameter of one end of the first spring seat 122 facing the first valve core body 121 is larger than the outer diameter of the other end, so that the first elastic member 123 can be sleeved outside the first spring seat 122 to facilitate the installation of the first elastic member 123, and the first elastic member 123 can be limited so that the first elastic member 123 will not bend when retracted.

[0055] The arrangement of the first elastic member 123 can ensure that only the first valve core body 121 can automatically reset after moving, and limit the movement of the valve stem 1211, so that the valve stem 1211 can move only by overcoming the elastic force of the first elastic member 123.

[0056] Exemplarily, the first elastic member 123 is a telescopic spring, and in an initial state, the first elastic member 123 is in a natural state.

[0057] Figure 4 for Figure 1 The exploded diagram of the first valve body, combined with Figure 4 Optionally, the first valve body 11 includes a first end plate 111, a second end plate 112 and a valve block 113, the first end plate 111 and the second end plate 112 are respectively located on opposite sides of the valve block 113, and the first end plate 111 and the second end plate 112 are respectively connected to the valve block 113.

[0058] A plate surface of the first end plate 111 facing the second end plate 112 has a first protrusion 1111 . The first protrusion 1111 is located in the valve block 113 and contacts the inner wall of the valve block 113 . The first protrusion 1111 is used to contact the first valve core body 121 .

[0059] The second end plate 112 has a second protrusion 1121 on a plate surface facing the first end plate 111 . The second protrusion 1121 is inserted into the first elastic member 123 , and the second end plate 112 abuts against one end of the first elastic member 123 .

[0060] In the above implementation, the first valve body 11 is configured as a first end plate 111 , a second end plate 112 and a valve block 113 , which facilitates the arrangement of the first valve core assembly 12 in the first valve body 11 and facilitates the processing and manufacturing of the first valve body 11 .

[0061] A first protrusion 1111 is arranged in the first end plate 111, and one end of the first valve core body 121 can be abutted by the first protrusion 1111, so that the first valve core body 121 can only move toward the second end plate 112 under the action of the oil pressure in the feedback oil port 1103. A second protrusion 1121 is arranged in the second end plate 112, and the first elastic member 123 can be further guided by the second protrusion 1121, so that the first elastic member 123 will not bend when it retracts.

[0062] Optionally, a feedback oil storage chamber 1112 is provided inside the first protrusion 1111 , and the feedback oil storage chamber 1112 is arranged along the length direction of the first protrusion 1111 and extends to an end surface of the first protrusion 1111 facing the first valve core assembly 12 .

[0063] The side wall of the first protrusion 1111 has a plurality of flow holes 1113 , which are arranged at intervals along the circumference of the first protrusion 1111 , and each of the plurality of flow holes 1113 is connected to the feedback oil storage chamber 1112 and the feedback oil port 1103 , respectively.

[0064] In the above implementation, a feedback oil storage chamber 1112 is arranged in the first protrusion 1111 and a flow hole 1113 is arranged in the side wall of the first protrusion 1111, so that the hydraulic oil in the feedback oil port 1103 can enter the feedback oil storage chamber 1112 through the flow hole 1113, so that the hydraulic oil in the feedback oil storage chamber 1112 directly acts on the end face of the first valve core body 121, so that the first valve core body 121 moves, and then controls the first oil inlet 1101 and the oil outlet 1102 to be connected or disconnected.

[0065] Continue to see Figure 4 Optionally, the valve block 113 has a strip cavity 1130 inside, and the length direction of the strip cavity 1130 is the same as the length direction and the moving direction of the first valve core body 121. The feedback oil port 1103 is located outside one end of the strip cavity 1130 and is in communication with the strip cavity 1130. The first oil inlet 1101 and the oil outlet 1102 are arranged outside the strip cavity 1130 at intervals along the length direction of the strip cavity 1130 and are both in communication with the strip cavity 1130. The first oil inlet 1101 is located between the feedback oil port 1103 and the oil outlet 1102, and a portion of the first oil inlet 1101 is located on the outer surface of the valve block 113. The first valve core body 121 is movably located in the strip-shaped cavity 1130 , and the first protrusion 1111 , the first outer flange 1212 , the second outer flange 1213 and the third outer flange 1214 in the first valve core body 121 are all in sliding contact with the inner wall of the strip-shaped cavity 1130 .

[0066] In the above implementation, the arrangement of the strip-shaped cavity 1130 can provide an accommodation space for the first valve core body 121. The reason why the first oil inlet 1101 and the oil outlet 1102 are arranged outside the strip-shaped cavity 1130 is that the first valve core body 121 can move so that a flow passage 1104 connecting the first oil inlet 1101 and the oil outlet 1102 can be formed between the first valve core body 121 and the inner wall of the first valve body 11.

[0067] In the disclosed embodiment, in order to improve the sealing performance of the first valve body 11 , sealing rings are sandwiched between the first end plate 111 and the valve block 113 , and between the second end plate 112 and the valve block 113 .

[0068] In order to facilitate assembly and disassembly, the first end plate 111 and the valve block 113 as well as the second end plate 112 and the valve block 113 may be connected by fasteners such as bolts.

[0069] Exemplarily, the valve block 113 also has a mounting hole 1131 for mounting the second valve body 21, the mounting hole 1131 extends from the inside of the valve block 113 to a side surface of the valve block 113, and the side surface where the mounting hole 1131 is located is arranged opposite to the side surface where the first oil inlet 1101 is located. The mounting hole 1131 is connected to the oil outlet 1102. The mounting hole 1131 is a threaded hole, and the second valve body 21 is inserted into the mounting hole 1131 by threads. In order to facilitate the connection between the mounting hole 1131 and the oil outlet 1102, the side of the mounting hole 1131 facing the oil outlet 1102 is a tapered opening, and the end with a smaller inner diameter of the tapered opening is connected to the oil outlet 1102 through the oil passage 1132.

[0070] Since the mounting hole 1131 is a threaded hole, the second valve body 21 is removable.

[0071] In order to simplify the design, the oil passage 1132 may be a common oil passage, and the oil passage 1132 may connect the oil outlet 1102 with the feedback oil port 1103 .

[0072] Figure 5 for Figure 1 The structural diagram of the throttle valve unit is shown in Figure 1. Figure 5 Optionally, the second valve body 21 includes a valve sleeve 211 and a throttle sleeve 212. The valve sleeve 211 is located at the oil outlet 1102 of the first valve body 11, and one end of the valve sleeve 211 is connected to the side wall of the first valve body 11. The throttle sleeve 212 is located in one end of the valve sleeve 211 facing the first valve body 11, and the throttle sleeve 212 is connected to the valve sleeve 211.

[0073] Figure 6 The schematic diagram of the throttling sleeve is shown in Figure 2. Figure 6 The throttle sleeve 212 has an inner flange 2121 at one end away from the first valve body 11. The throttle oil port 2102 passes through the opposite end surfaces of the inner flange 2121 along the axis of the inner flange 2121, and the inner hole of the inner flange 2121 defines a second oil inlet 2101.

[0074] In the above implementation, the valve sleeve 211 is used to connect with the first valve body 11, and at the same time provides a mounting base for the throttle sleeve 212, and is used to form the unloading oil port 2103. The throttle sleeve 212 is used to receive the hydraulic oil discharged from the pressure reducing valve unit 1, and is also used to connect with the valve sleeve 211 to define the throttle oil port 2102 and the second oil inlet 2101.

[0075] That is to say, the above structure can simply form the second oil inlet 2101 , the throttling oil port 2102 and the unloading oil port 2103 in the second valve body 21 .

[0076] In the disclosed embodiment, the inner part of the valve sleeve 211 facing the end of the first valve body 11 has an internal thread, and the outer wall of the throttle sleeve 212 has an external thread, and the throttle sleeve 212 and the valve sleeve 211 are connected together by threads. This facilitates the disassembly and assembly of the two. In order to further facilitate the threaded connection of the throttle sleeve 212 in the valve sleeve 211, the inner part of the throttle sleeve 212 is hexagonal, which makes it convenient to install the throttle sleeve 212 using a hexagonal wrench. The outer wall of the valve sleeve 211 has an external thread, and the valve sleeve 211 is inserted into the mounting hole 1131 and connected by threads. Since the valve sleeve 211 and the throttle sleeve 212 are threadedly connected, the throttle sleeve 212 with throttle oil ports 2102 of different sizes can be selected according to different pressure flows.

[0077] There are multiple throttling oil ports 2102, and the multiple throttling oil ports 2102 are arranged in the side wall of the inner flange 2121 at intervals along the circumference of the inner flange 2121. In this way, the inner flange 2121 can provide a basis for the arrangement of the throttling oil ports 2102, so that the throttling oil ports 2102 can be simply arranged. In the embodiment of the present disclosure, there are four throttling oil ports 2102, and the four throttling oil ports 2102 are evenly distributed along the circumference of the inner flange 2121.

[0078] The inner flange 2121 can be an integrally cast structural part with the throttle sleeve 212, or can be welded to the inner wall of the throttle sleeve 212. The throttle oil port 2102 is formed by rotary cutting with an involute profile, which is conducive to the smooth passage of hydraulic oil.

[0079] See again Figure 5 , optionally, the unloading oil port 2103 is located in the middle of the valve sleeve 211. The second valve core assembly 22 includes a second valve core body 221, which is movably located in the valve sleeve 211 and is located at an end of the throttle sleeve 212 away from the first valve body 11. When the pressure at the second oil inlet 2101 is greater than the second threshold value, the second valve core body 221 is spaced from the throttle sleeve 212, and a communication channel connecting the unloading oil port 2103 and the second oil inlet 2101 is formed between the outer wall of the second valve core body 221 and the valve sleeve 211. When the pressure at the second oil inlet 2101 is not greater than the second threshold value, the second valve core body 221 blocks the inner hole of the inner flange 2121.

[0080] In the above implementation, by controlling the movement of the second valve core body 221 , it is possible to control whether the unloading oil port 2103 and the second oil inlet 2101 are connected.

[0081] In order to store more hydraulic oil, the unloading oil port 2103 is an annular cavity, and a portion of the unloading oil port 2103 extends to the outer wall of the valve sleeve 211 .

[0082] Optionally, the outer wall of the second valve core body 221 facing the throttle sleeve 212 has a first sealing bevel 2210. The inner wall of the throttle sleeve 212 facing the second valve core body 221 has a second sealing bevel 2120, and when the pressure at the second oil inlet 2101 is not greater than the second threshold, the first sealing bevel 2210 and the second sealing bevel 2120 fit together.

[0083] In the above implementation, the cooperation between the first sealing bevel 2210 and the second sealing bevel 2120 can increase the contact area between the second valve core body 221 and the throttling sleeve 212, thereby improving the sealing effect of the two.

[0084] Figure 7 is a schematic diagram of the structure of the second valve core body, combined with Figure 7 In the disclosed embodiment, the second valve core body 221 is a rod-shaped structure, and the second valve core body 221 includes a constricted section 2211 and a flared section 2212 connected to each other along the length direction of the second valve core body 221, the constricted section 2211 is located between the flared section 2212 and the throttling sleeve 212, and the flared section 2212 is located on the side of the unloading oil port 2103 away from the throttling sleeve 212. The outer diameter of the constricted section 2211 is smaller than the outer diameter of the flared section 2212, the outer wall of the constricted section 2211 is spaced apart from the inner wall of the valve sleeve 211, and the flared section 2212 is in sliding contact with the inner wall of the valve sleeve 211. In this way, a communication channel connecting the unloading oil port 2103 and the second oil inlet 2101 can be formed between the constricted section 2211 with a smaller outer diameter and the inner wall of the valve sleeve 211. At the same time, the flared section 2212 is arranged on the side of the unloading oil port 2103 away from the throttling sleeve 212 , so that the hydraulic oil can be unloaded from the unloading oil port 2103 first, and will not leak out from between the flared section 2212 and the valve sleeve 211 .

[0085] The expanded section 2212 has a spring cavity inside for installing a second elastic member 223 (to be introduced below), and one end of the spring cavity extends to an end surface of the expanded section 2212 away from the contracted section 2211 .

[0086] See again Figure 5 Optionally, the second valve core assembly 22 also includes a second elastic member 223, which is located in the valve sleeve 211, and the second elastic member 223 is located on the side of the second valve core body 221 away from the throttling sleeve 212, and the two ends of the second elastic member 223 are respectively against the valve sleeve 211 and the second valve core body 221.

[0087] In the above implementation, the arrangement of the second elastic member 223 allows the second valve core body 221 to automatically reset after movement and isolate the second oil inlet 2101 and the unloading oil port 2103, thereby closing the back pressure valve unit 2 for reuse, and at the same time restricting the movement of the second valve core body 221, so that the second valve core body 221 can move only after overcoming the elastic force of the second elastic member 223.

[0088] Optionally, the valve sleeve 211 includes a sleeve body 2111, a valve cover 2112 and a second spring seat 2113, one end of the sleeve body 2111 is connected to the first valve body 11, the valve cover 2112 is located at the other end of the sleeve body 2111, and is movably connected to the sleeve body 2111 so that the valve cover 2112 can move toward or away from the second elastic member 223 relative to the sleeve body 2111.

[0089] The second spring seat 2113 is located in the sleeve body 2111, and one end of the second spring seat 2113 contacts the valve cover 2112, and the other end is inserted into the second elastic member 223 and abuts against the end surface of the second elastic member 223. The second elastic member 223 is inserted into the second valve core body 221 at one end thereof facing the second valve core body 221.

[0090] In the above implementation, the sleeve body 2111 is used to provide a mounting base for the second elastic member 223, the second valve core body 221, etc. The valve cover 2112 is used to be movably connected with the sleeve body 2111 so as to apply different forces to the second spring seat 2113. The second spring seat 2113 is used to abut against the second elastic member 223 so as to adjust the set pressure of the second elastic member 223, thereby changing the size of the second threshold value, so that the pressure of the back pressure valve is adjustable and has a strong impact resistance.

[0091] In the disclosed embodiment, the valve cover 2112 is partially inserted into the sleeve body 2111, and the valve cover 2112 and the sleeve body 2111 are fixed together by bolts or the like. The valve cover 2112 has a threaded hole inside, in which a screw rod 2114 is inserted, and a nut 2115 is disposed outside the screw rod. By adjusting the length of the screw rod 2114 extending into the valve sleeve 211, the pressure of the valve cover 2112 on the second spring seat 2113 can be changed, thereby adjusting the preset elastic force of the second elastic member 223.

[0092] Figure 8 It is a schematic diagram of the structure of the sleeve body. Figure 8Optionally, the sleeve body 2111 has a first positioning stop 201 and a second positioning stop 202 at opposite ends thereof, the first positioning stop 201 is arranged toward the first valve body 11, the second positioning stop 202 is arranged away from the first valve body 11, and the first positioning stop 201 is located on the side of the throttle sleeve 212 away from the first valve body 11. The first positioning stop 201 is used for clamping the throttle sleeve 212. The inner wall between the end surface of the sleeve body 2111 facing the first valve body 11 and the first positioning stop 201 has an internal thread, so that the throttle sleeve 212 can be installed in the sleeve body 2111 through the internal thread, and the throttle sleeve 212 is positioned and clamped by the first positioning stop 201 to prevent the throttle sleeve 212 from sliding into the valve sleeve 211. The second positioning stop 202 is located on the side of the valve cover 2112 facing the first valve body 11, and the second positioning stop 202 is clamped with the valve cover 2112. The second positioning stop 202 is used to position the valve cover 2112 so that the valve cover 2112 will not fall into the sleeve body 2111 .

[0093] The following briefly introduces the working process of the back pressure valve provided in the embodiment of the present disclosure:

[0094] The hydraulic oil at the pump outlet enters the first valve body 11 through the first oil inlet 1101, and enters the oil outlet 1102 through the notch 1105 in the first valve core body 121. A portion of the hydraulic oil in the oil outlet 1102 enters the second oil inlet 2101, and the other portion enters the feedback oil port 1103. The hydraulic oil in the feedback oil port 1103 enters the feedback oil storage chamber 1112 through the circulation hole 1113, and the hydraulic oil in the feedback oil storage chamber 1112 acts on the end surface of the first valve core body 121.

[0095] When the pressure of the hydraulic oil at the oil outlet 1102 is too high, the pressure of the hydraulic oil in the feedback oil storage chamber 1112 increases accordingly. When the pressure of the hydraulic oil in the feedback oil storage chamber 1112 is large enough to push the first valve core body 121 to overcome the elastic force of the first elastic member 123 and move right, the flow area of ​​the flow channel 1104 decreases, and the pressure of the hydraulic oil at the oil outlet 1102 decreases to achieve pressure reduction.

[0096] The hydraulic oil after decompression enters the second oil inlet 2101 again. At this time, the second valve core body 221 closes the second oil inlet 2101 under the elastic force of the second elastic member 223, so that the hydraulic oil can only be discharged through the throttling oil port 2102 to the unloading oil port 2103. When the flow rate of the hydraulic oil in the second oil inlet 2101 is large, a large pressure loss will be generated at the throttling oil port 2102. When the pressure loss increases to exceed the set pressure of the second elastic member 223, the second valve core body 221 moves, and the second valve core body 221 and the throttling sleeve 212 are spaced to form a connecting channel connecting the second oil inlet 2101 and the unloading oil port 2103. The hydraulic oil directly enters the unloading oil port 2103 from the second oil inlet 2101, which greatly increases the effective flow area of ​​the hydraulic oil, reduces the pressure drop, and thus reduces the pressure at the pump outlet and reduces energy loss.

[0097] The back-pressure valve provided in the embodiment of the present disclosure can be directly connected to the pump outlet without being connected through a pipeline, thereby reducing the liquid resistance of the hydraulic oil in the pipeline and having the effect of energy saving and consumption reduction. Therefore, the back-pressure valve can effectively reduce the energy loss of the hydraulic pump, reduce system heating, and save energy and protect the environment. Moreover, the back-pressure valve is integrated through the pressure reducing valve unit 1 and the back-pressure valve unit 2, and has a compact size and is easy to install. At the same time, since the feedback oil port 1103 is provided in the pressure reducing valve unit 1, the back-pressure valve has a feedback adjustment function, which makes the movement of the back-pressure valve more stable and reduces vibration.

[0098] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A back pressure valve, characterized in that: The back-pressure valve comprises a pressure reducing valve unit (1) and a back-pressure valve unit (2); the pressure reducing valve unit (1) comprises a first valve body (11) and a first valve core assembly (12); the first valve body (11) has a first oil inlet (1101), an oil outlet (1102) and a feedback oil port (1103); the oil outlet (1102) is respectively connected to the first oil inlet (1101) and the feedback oil port (1103); The first valve core component (12) is movably located in the first valve body (11), and the first valve core component (12) is configured to: when the pressure at the feedback oil port (1103) is not greater than a first threshold, connect the first oil inlet (1101) and the oil outlet (1102), and when the pressure at the feedback oil port (1103) is greater than the first threshold, control the connection area between the first oil inlet (1101) and the oil outlet (1102), and the connection area decreases as the pressure at the feedback oil port (1103) increases; The back pressure valve unit (2) comprises a second valve body (21) and a second valve core assembly (22); the second valve body (21) is connected to the first valve body (11); the second valve body (21) has a second oil inlet (2101), a throttling oil port (2102) and a relief oil port (2103); the second oil inlet (2101) is connected to the oil outlet (1102); two ends of the throttling oil port (2102) are respectively connected to the second oil inlet (2101) and the relief oil port (2103); the flow area of ​​the relief oil port (2103) is greater than the flow area of ​​the throttling oil port (2102), and the relief oil port (2103) is connected to the oil tank; The second valve core assembly (22) is movably located in the second valve body (21), and the second valve core assembly (22) is configured to: when the pressure at the second oil inlet (2101) is greater than a second threshold value, connect the second oil inlet (2101) and the unloading oil port (2103); when the pressure at the second oil inlet (2101) is not greater than the second threshold value, isolate the second oil inlet (2101) from the unloading oil port (2103), and the second threshold value is greater than the first threshold value.

2. The back pressure valve according to claim 1, characterized in that: The first valve core assembly (12) comprises a first valve core body (121), the first valve core body (121) is movably located in the first valve body (11), and one end of the first valve core body (121) faces the feedback oil port (1103); The first valve core body (121) comprises a valve stem (1211) and a first outer flange (1212) arranged on the middle outer wall of the valve stem (1211); the outer wall of the first outer flange (1212) is in sliding contact with the inner wall of the first valve body (11); the first outer flange (1212) is located between the first oil inlet (1101) and the oil outlet (1102); when the pressure at the feedback oil port (1103) is not greater than a first threshold value, a flow passage (1104) connecting the first oil inlet (1101) and the oil outlet (1102) is formed between the first outer flange (1212) and the inner wall of the first valve body (11); when the pressure at the feedback oil port (1103) is greater than the first threshold value, the flow area of ​​the flow passage (1104) gradually decreases.

3. The back pressure valve according to claim 2, characterized in that: The outer wall of one end of the first outer flange (1212) facing the oil outlet (1102) has a plurality of notches (1105), and the plurality of notches (1105) are arranged at intervals along the circumference of the first outer flange (1212), and each notch (1105) of the plurality of notches (1105) extends from the end surface of the first outer flange (1212) facing the oil outlet (1102) toward the outer wall of the first outer flange (1212).

4. The back pressure valve according to claim 2, characterized in that: The first valve core assembly (12) further comprises a first spring seat (122) and a first elastic member (123); the first spring seat (122) is located at an end of the first valve core body (121) away from the feedback oil port (1103), and is connected to one end of the first valve core body (121); The first elastic member (123) is sleeved on the other end of the first spring seat (122) away from the first valve core body (121), and the two ends of the first elastic member (123) are respectively against the first spring seat (122) and the inner wall of the first valve body (11).

5. The back pressure valve according to claim 4, characterized in that: The first valve body (11) comprises a first end plate (111), a second end plate (112) and a valve block (113); the first end plate (111) and the second end plate (112) are respectively located on two opposite sides of the valve block (113); and the first end plate (111) and the second end plate (112) are respectively connected to the valve block (113); A plate surface of the first end plate (111) facing the second end plate (112) has a first protrusion (1111), and the first protrusion (1111) is located in the valve block (113) and is used to contact one end of the first valve core body (121); A plate surface of the second end plate (112) facing the first end plate (111) has a second protrusion (1121), the second protrusion (1121) is inserted into the first elastic member (1233), and the second end plate (112) abuts against one end of the first elastic member (123).

6. The back pressure valve according to claim 5, characterized in that: A feedback oil storage chamber (1112) is provided inside the first protrusion (1111), and the feedback oil storage chamber (1112) is arranged along the length direction of the first protrusion (1111) and extends to an end surface of the first protrusion (1111) facing the first valve core assembly (12); The side wall of the first protrusion (1111) has a plurality of circulation holes (1113), and the plurality of circulation holes (1113) are arranged at intervals along the circumference of the first protrusion (1111), and each of the plurality of circulation holes (1113) is respectively connected to the feedback oil storage chamber (1112) and the feedback oil port (1103).

7. The back pressure valve according to any one of claims 1 to 6, characterized in that: The second valve body (21) comprises a valve sleeve (211) and a throttle sleeve (212); The valve sleeve (211) is located at the oil outlet (1102) of the first valve body (11), and one end of the valve sleeve (211) is connected to the side wall of the first valve body (11); The throttling sleeve (212) is located inside one end of the valve sleeve (211) facing the first valve body (11), and the throttling sleeve (212) is connected to the valve sleeve (211); The throttling sleeve (212) has an inner flange (2121) in the inner wall of one end away from the first valve body (11), and the throttling oil port (2102) passes through the opposite end surfaces of the inner flange (2121) along the axis of the inner flange (2121), and the inner hole of the inner flange (2121) defines the second oil inlet (2101).

8. The back pressure valve according to claim 7, characterized in that: The unloading oil port (2103) is located in the middle of the valve sleeve (211); The second valve core assembly (22) includes a second valve core body (221), which is movably located in the valve sleeve (211) and is located at the end of the throttling sleeve (212) away from the first valve body (11). When the pressure at the second oil inlet (2101) is greater than a second threshold value, the second valve core body (221) is spaced apart from the throttling sleeve (212), and a connecting passage connecting the unloading oil port (2103) and the second oil inlet (2101) is formed between the outer wall of the second valve core body (221) and the valve sleeve (211). When the pressure at the second oil inlet (2101) is not greater than the second threshold value, the second valve core body (221) blocks the inner hole of the inner flange (2121).

9. The back pressure valve according to claim 8, characterized in that: The outer wall of one end of the second valve core body (221) facing the throttling sleeve (212) is provided with a first sealing inclined surface (2210); The throttling sleeve (212) has a second sealing bevel (2120) on its inner wall at one end facing the second valve core body (221), and when the pressure at the second oil inlet (2101) is not greater than a second threshold value, the first sealing bevel (2210) and the second sealing bevel (2120) fit together.

10. The back pressure valve according to claim 8, characterized in that: The second valve core assembly (22) further comprises a second elastic member (223), wherein the second elastic member (223) is located in the valve sleeve (211), and the second elastic member (223) is located on a side of the second valve core body (221) away from the throttling sleeve (212), and the two ends of the second elastic member (223) are respectively against the valve sleeve (211) and the second valve core body (221).

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