Back pressure valve

Abstract

This disclosure provides a back pressure valve, belonging to the field of valve technology. The back pressure valve includes a pressure reducing valve unit and a back pressure valve assembly. The pressure reducing valve unit includes a first valve body and a first valve core assembly. The first valve body has a first oil inlet, an oil outlet, and a feedback oil port. The first valve core assembly is movably located within the first valve body. The back pressure valve unit includes a second valve body and a second valve core assembly. The second valve body has a second oil inlet, a throttling oil port, and an unloading oil port arranged at intervals. The second oil inlet communicates with the oil outlet. The throttling oil port communicates with both the second oil inlet and the unloading oil port. The flow area of ​​the unloading oil port is larger than that of the throttling oil port. The second valve core assembly is movably located within the second valve body. This disclosure can reduce vibration and noise.

Description

Technical Field

[0001] This disclosure belongs to the field of valve technology, and specifically relates to a back pressure valve. Background Technology

[0002] Back pressure valves are important instruments in industrial automation process control, used to prevent liquids from flowing out by gravity or siphoning. They are typically installed at the pump outlet, not only to stabilize the pump's output flow but also as safety valves in less demanding applications.

[0003] In related technologies, a back pressure valve includes a valve body, a diaphragm, and a spring. The valve body has an inlet and a throttle port. Both the diaphragm and the spring are located within the valve body, with the diaphragm positioned at the inlet and abutting against one end of the spring. Hydraulic oil enters the safety valve through the inlet and contacts the diaphragm. The throttle port is used to discharge hydraulic oil from the back pressure valve. When the hydraulic oil pressure at the inlet is greater than the spring force, the diaphragm is pushed up by the hydraulic oil, creating a passage between the inlet and the throttle port, opening the back pressure valve and achieving pressure limiting. Conversely, when the hydraulic oil pressure at the inlet is insufficient to push up the diaphragm, the inlet and throttle port disconnect, and the back pressure valve holds pressure until the hydraulic oil pressure at the inlet reaches the spring force (i.e., the rated pressure).

[0004] However, in the back pressure valves mentioned above, since the back pressure valve can only release pressure through the throttling orifice, as the pump outlet pressure and flow gradually increase, the pressure loss generated at the throttling orifice during pressure release will be larger, which will cause greater vibration and noise, resulting in poor working condition of the back pressure valve and affecting the pump outlet pressure. Summary of the Invention

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

[0006] This disclosure provides a back pressure valve, which includes a pressure reducing valve unit and a back pressure valve unit. The pressure reducing valve unit includes a first valve body and a first valve core assembly. The first valve body has a first oil inlet, an oil outlet, and a feedback oil port. The oil outlet is connected to the first oil inlet and the feedback oil port, respectively. The first valve core assembly is movably located within the first valve body and 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, and control the connection area between the first oil inlet and the oil outlet when the pressure at the feedback oil port is greater than the first threshold. The connection area decreases as the pressure at the feedback oil port increases. The back pressure valve unit includes a second valve body and a... The second valve core assembly is connected to the first valve body. The second valve body has a second oil inlet, a throttling oil inlet, and an unloading oil inlet. The second oil inlet is connected to the oil outlet. The two ends of the throttling oil inlet are connected to the second oil inlet and the unloading oil inlet, respectively. The flow area of ​​the unloading oil inlet is larger than that of the throttling oil inlet, and the unloading oil inlet is connected to the oil tank. The second valve core assembly is movably located in the second valve body and is configured to: connect the second oil inlet and the unloading oil inlet when the pressure at the second oil inlet is greater than a second threshold, and disconnect the second oil inlet and the unloading oil inlet when the pressure at the second oil inlet is not greater than the second threshold, wherein the second threshold is greater than the first threshold.

[0007] In another implementation of this disclosure, the first valve core assembly includes a first valve core body, which is movably located within the first valve body, with one end of the first valve core body facing the feedback port. The first valve core body includes a valve stem and a first outer flange disposed on the middle outer wall of the valve stem. The outer wall of the first outer flange slides in contact with the inner wall of the first valve body. The first outer flange is located between the first inlet port and the outlet port. When the pressure at the feedback port is not greater than a first threshold, a flow channel connecting the first inlet port and the outlet port is formed between the first outer flange and the inner wall of the first valve body. When the pressure at the feedback port is greater than the first threshold, the flow area of ​​the flow channel gradually decreases.

[0008] In another implementation of this disclosure, the outer wall of the end of the first outer flange facing the oil outlet has a plurality of notches, the plurality of notches being arranged at intervals along the circumference of the first outer flange, and each of the plurality of notches extending from the end of the first outer flange facing the oil outlet toward the outer wall of the first outer flange.

[0009] In another implementation of this disclosure, the first valve core assembly further includes a first spring seat and a first elastic element. 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 element is sleeved on the other end of the first spring seat away from the first valve core body, and both ends of the first elastic element abut against the inner walls of the first spring seat and the first valve body, respectively.

[0010] In another implementation of this 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 located on opposite sides of the valve block and are connected to the valve block. The first end plate has a first protrusion on one side facing the second end plate. The first protrusion is located inside the valve block and is used to contact one end of the first valve core body. The second end plate has a second protrusion on one side facing the first end plate. The second protrusion is inserted into the first elastic member, and the second end plate abuts against one end of the first elastic member.

[0011] In another implementation of this disclosure, the first protrusion has a feedback oil storage chamber inside, the feedback oil storage chamber is arranged along the length direction of the first protrusion and extends to one end face of the first protrusion facing the first valve core assembly; the sidewall of the first protrusion has a plurality of flow holes, 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 connected to the feedback oil storage chamber and the feedback oil port respectively.

[0012] In another implementation of this disclosure, the second valve body includes a valve sleeve and a throttling 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 throttling sleeve is located inside the end of the valve sleeve facing the first valve body, and the throttling sleeve is connected to the valve sleeve; the inner wall of the end of the throttling sleeve away from the first valve body has an inner flange, and the throttling oil port passes through the opposite two end faces 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 this disclosure, the unloading port is located in the middle of the valve sleeve; the second valve core assembly includes a second valve core body, which is movably located inside the valve sleeve and at the end of the throttling sleeve away from the first valve body. When the pressure at the second inlet is greater than a second threshold, the second valve core body is spaced apart from the throttling sleeve, and a connecting channel is formed between the outer wall of the second valve core body and the valve sleeve, connecting the unloading port and the second inlet. When the pressure at the second inlet is not greater than the second threshold, the second valve core body blocks the inner hole of the inner flange.

[0014] In another implementation of this disclosure, the outer wall of the second valve core body facing the end of the throttling sleeve has a first sealing slope; the inner wall of the throttling sleeve facing the end of the second valve core body has a second sealing slope, and when the pressure at the second oil inlet is not greater than the second threshold, the first sealing slope and the second sealing slope are in contact.

[0015] In another implementation of this disclosure, the second valve core assembly further includes a second elastic member located inside the valve sleeve and on the side of the second valve core body away from the throttling sleeve, with both ends of the second elastic member abutting against the valve sleeve and the second valve core body, respectively.

[0016] The beneficial effects of the technical solutions provided in this disclosure are:

[0017] When the back pressure valve provided in this embodiment is connected to the pump outlet, the pump outlet is connected to the first inlet. Hydraulic oil flowing from the pump outlet enters the first valve body through the first inlet. Since the hydraulic oil has not yet entered the outlet, the pressure at the feedback port is zero. At this time, the first valve core assembly enables the first inlet and the outlet to connect, allowing hydraulic oil to enter the outlet. As the oil pressure at the pump outlet increases, the oil pressure at the outlet also increases. Since the feedback port is connected to the outlet, the oil pressure at the feedback port also increases. When the pressure at the feedback port exceeds a first threshold, as the pressure at the feedback port increases, the connection area between the first inlet and the outlet gradually decreases, thus gradually reducing the oil pressure at the outlet and achieving pressure reduction.

[0018] A portion of the hydraulic oil entering the outlet enters the feedback port to adjust the communication area between the first inlet and the outlet, while the remaining hydraulic oil enters the second valve body through the second inlet. Since the throttling port is connected to both the second inlet and the unloading port, the hydraulic oil entering the second inlet is throttled before being discharged through the unloading port. As the oil pressure at the outlet gradually increases, the pressure at the second inlet also gradually increases. When the pressure at the second inlet exceeds a second threshold, the second inlet and the unloading port connect, allowing the hydraulic oil in the second inlet to be directly discharged through the unloading port, thus relieving pressure. Because the flow area of ​​the unloading port is larger than that of the throttling port, the pressure drop of the hydraulic fluid entering and exiting the back pressure valve can be reduced through the unloading port, thereby reducing the vibration and noise of the back pressure valve and achieving noise and vibration reduction.

[0019] In other words, when the pump outlet pressure is low, the back pressure valve provided in this embodiment directly discharges the hydraulic oil through the throttling port, resulting in a low pressure of the discharged hydraulic oil. As the pump outlet pressure gradually increases, the hydraulic oil is first depressurized through the outlet port and then enters the throttling port before being discharged, ensuring that the pressure of the discharged hydraulic oil is still not too high. When the pump outlet pressure is very high, until the pressure at the second inlet port exceeds the second threshold, the hydraulic oil is not only discharged through the throttling port but also directly unloaded through the unloading port, limiting the pump outlet pressure and keeping it within a relatively stable range, thereby achieving the functions of pressure stabilization and noise reduction. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a back pressure valve provided in an embodiment of this disclosure;

[0022] Figure 2 This is a three-dimensional schematic diagram of the 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 view of the first valve body;

[0025] Figure 5 for Figure 1 Schematic diagram of the structure of the throttle valve unit;

[0026] Figure 6 This is a schematic diagram of the throttling sleeve.

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

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

[0029] The symbols in the diagram represent the following meanings:

[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 chamber; 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 element;

[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. Throttling sleeve; 2121. Inner flange; 2101. Second oil inlet; 2102. Throttling oil port; 2103. Unloading oil port; 22. Second valve core assembly; 221. Second valve core body; 2211. Narrowing section; 2212. Flaring section; 2210. First sealing bevel; 2120. Second sealing bevel; 223. Second elastic element; 201. First positioning stop; 202. Second positioning stop. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0033] This disclosure provides a back pressure valve, such as 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 outlet 1103. The oil outlet 1102 is connected to the first oil inlet 1101 and the feedback oil outlet 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, and control the connection 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, wherein the connection 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. 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 inlet 2102, and an unloading oil inlet 2103 arranged at intervals. The second oil inlet 2101 is connected to the oil outlet 1102. The throttling oil inlet 2102 is connected to both the second oil inlet 2101 and the unloading oil inlet 2103. The flow area of ​​the unloading oil inlet 2103 is larger than that of the throttling oil inlet 2102. The unloading oil inlet 2103 is connected to the oil tank to recover oil into the oil tank.

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

[0037] When using the back pressure valve provided in this embodiment, for example, the back pressure valve can be connected to the pump outlet. 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, allowing the hydraulic oil to enter the oil outlet 1102. As the oil pressure at the pump outlet continuously increases, the oil pressure at the oil outlet 1102 also continuously increases. Since the feedback oil port 1103 is connected to the oil outlet 1102, the oil pressure at the feedback oil port 1103 also continuously increases. When the pressure at the feedback port 1103 is greater than the first threshold, as the pressure at the feedback port 1103 continues to increase, the connection area between the first inlet port 1101 and the outlet port 1102 gradually decreases, so the oil pressure at the outlet port 1102 gradually decreases.

[0038] Since the second inlet 2101 is connected to the outlet 1102, a portion of the hydraulic oil entering the outlet 1102 enters the feedback port 1103 to adjust the communication area between the first inlet 1101 and the outlet 1102, while the other portion of the hydraulic oil enters the second valve body 21 through the second inlet 2101. Because the throttling port 2102 is connected to both the second inlet 2101 and the unloading port 2103, the hydraulic oil entering the second inlet 2101 is throttled by the throttling port 2102 and then discharged through the unloading port 2103. As the oil pressure at the outlet 1102 gradually increases, the pressure at the second inlet 2101 also gradually increases. When the pressure at the second inlet 2101 exceeds the second threshold, the second inlet 2101 and the unloading port 2103 become connected. Therefore, the hydraulic oil in the second inlet 2101 is directly discharged through the unloading port 2103 to relieve pressure. Since the flow area of ​​the unloading port 2103 is larger than that of the throttling port 2102, the pressure drop can be reduced through the unloading port 2103, thereby reducing the pump outlet pressure and energy loss.

[0039] In other words, when the pump outlet pressure is low, the back pressure valve provided in this embodiment directly throttles and discharges the hydraulic oil through the throttling port 2102, resulting in a low pressure of the discharged hydraulic oil. As the pump outlet pressure gradually increases, the hydraulic oil is first depressurized through the outlet port 1102 and then enters the throttling port 2102 before being discharged, ensuring that the pressure of the discharged hydraulic oil is still not too high. When the pump outlet pressure is very high, until the pressure at the second inlet port 2101 exceeds the second threshold, the hydraulic oil is not only discharged through the throttling port 2102, but also directly unloaded through the unloading port 2103, limiting the pump outlet pressure and keeping it within a relatively stable range, thereby achieving the functions of pressure stabilization and noise reduction.

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

[0041] Figure 2 This is a three-dimensional schematic diagram of the first valve core assembly, combined with... Figure 2 The first valve core body 121 includes a valve stem 1211 and a first outer flange 1212 disposed on the outer wall of the middle part 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.

[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 outlet 1103 is not greater than the first threshold, a flow passage 1104 is formed between the first outer flange 1212 and the inner wall of the first valve body 11, connecting the first oil inlet 1101 and the oil outlet 1102. When the pressure at the feedback oil outlet 1103 is greater than the first threshold, the flow area of ​​the flow passage 1104 gradually decreases.

[0043] In the above implementation, the first valve core body 121 is configured with the above structure, and the first outer flange 1212 can be moved by the movement of the valve stem 1211, thereby controlling whether the first oil inlet 1101 and the oil outlet 1102 are connected.

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

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

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

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

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

[0049] See also Figure 2Optionally, the first valve core body 121 further includes a second outer flange 1213 and a third outer flange 1214. The second outer flange 1213 and the third outer flange 1214 are located outside both 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 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. Both the second outer flange 1213 and the third outer flange 1214 are 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 along its length, and the third outer flange 1214 is spaced apart from the other end of the first valve body 11 along its length.

[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 arbitrarily.

[0051] Figure 3 for Figure 1 A schematic diagram of the structure of the first valve core body, combined with Figure 3 In this embodiment, for ease of configuration, 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 you again Figure 1 Optionally, the first valve core assembly 12 further includes a first spring seat 122 and a first elastic element 123. The first spring seat 122 is located at one end of the first valve core body 121 away from the feedback port 1103 and is connected to one end of the first valve core body 121. The outer diameter of the end of the first spring seat 122 facing the first valve core body 121 is larger than the outer diameter of the other end.

[0053] The first elastic element 123 is fitted onto 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 element 123 abut against the inner walls of the first spring seat 122 and 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. Simultaneously, the outer diameter of the end of the first spring seat 122 facing the first valve core body 121 is larger than the outer diameter of the other end. This allows the first elastic member 123 to be fitted over the first spring seat 122, facilitating the installation of the first elastic member 123, and also limiting the first elastic member 123 so that it does not bend during retraction.

[0055] The arrangement of the first elastic element 123 allows only the first valve core body 121 to automatically reset after movement, and restricts the movement of the valve stem 1211, so that the valve stem 1211 can only move by overcoming the elastic force of the first elastic element 123.

[0056] For example, the first elastic element 123 is a telescopic spring, and in the initial state, the first elastic element 123 is in its natural state.

[0057] Figure 4 for Figure 1 An exploded view 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 located on opposite sides of the valve block 113, and the first end plate 111 and the second end plate 112 are connected to the valve block 113.

[0058] The first end plate 111 has a first protrusion 1111 on one side facing the second end plate 112. The first protrusion 1111 is located inside 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 one side 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. On the one hand, it is convenient for the first valve core assembly 12 to be arranged in the first valve body 11, and on the other hand, it is also convenient for the processing and manufacturing of the first valve body 11.

[0061] A first protrusion 1111 is arranged in the first end plate 111, which abuts against one end of the first valve core body 121, so that the first valve core body 121 can only move towards the second end plate 112 under the action of oil pressure in the feedback oil port 1103. A second protrusion 1121 is provided in the second end plate 112, which can further guide the first elastic member 123, so that the first elastic member 123 will not bend when it retracts.

[0062] Optionally, the first protrusion 1111 has a feedback oil reservoir 1112 inside, which is arranged along the length of the first protrusion 1111 and extends to one end face of the first protrusion 1111 facing the first valve core assembly 12.

[0063] The sidewall 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. This allows the hydraulic oil in the feedback oil port 1103 to enter the feedback oil storage chamber 1112 after passing through the flow hole 1113. The hydraulic oil in the feedback oil storage chamber 1112 then acts directly on the end face of the first valve core body 121, causing the first valve core body 121 to move, thereby controlling the connection or disconnection of the first oil inlet 1101 and the oil outlet 1102.

[0065] See also Figure 4 Optionally, the valve block 113 has a strip-shaped cavity 1130 inside, the length direction of which is the same as the length direction and the direction of movement of the first valve core body 121. The feedback port 1103 is located outside one end of the strip-shaped cavity 1130 and communicates with the strip-shaped cavity 1130. The first inlet port 1101 and the outlet port 1102 are arranged at intervals outside the strip-shaped cavity 1130 along the length direction of the strip-shaped cavity 1130 and are both communicated with the strip-shaped cavity 1130. The first inlet port 1101 is located between the feedback port 1103 and the outlet port 1102, and part of the first inlet port 1101 is located on the outer surface of the valve block 113. The first valve core body 121 is movably located in the strip 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 cavity 1130.

[0066] In the above implementation, the arrangement of the strip cavity 1130 can provide accommodating space for the first valve core body 121. The reason for arranging the first oil inlet 1101 and the oil outlet 1102 at intervals outside the strip cavity 1130 is that the movement of the first valve core body 121 can form a flow channel 1104 connecting the first oil inlet 1101 and the oil outlet 1102 between the first valve core body 121 and the inner wall of the first valve body 11.

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

[0068] To facilitate disassembly and assembly, bolts or other fasteners can be used to connect the first end plate 111 and the valve block 113, as well as the second end plate 112 and the valve block 113.

[0069] For example, the valve block 113 also has a mounting hole 1131 for mounting the second valve body 21. The mounting hole 1131 extends from the interior of the valve block 113 to one side of the valve block 113, and the side where the mounting hole 1131 is located is arranged opposite to the side where the first oil inlet 1101 is located. The mounting hole 1131 communicates with the oil outlet 1102. The mounting hole 1131 is a threaded hole, and the second valve body 21 is threaded into the mounting hole 1131. In order to facilitate the communication between the mounting hole 1131 and the oil outlet 1102, the side of the mounting hole 1131 facing the oil outlet 1102 is tapered, and the end with the smaller inner diameter of the tapered opening communicates with the oil outlet 1102 through an oil passage 1132.

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

[0071] To simplify the design, the oil passage 1132 can be a shared oil passage, and the oil passage 1132 can connect the oil outlet 1102 and the feedback oil port 1103.

[0072] Figure 5 for Figure 1 A schematic diagram of the structure of the throttle valve unit, combined with... Figure 5 Optionally, the second valve body 21 includes a valve sleeve 211 and a throttling 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 the end of the valve sleeve 211 facing the first valve body 11, and the throttling sleeve 212 is connected to the valve sleeve 211.

[0073] Figure 6 This is a schematic diagram of the throttling sleeve, combined with... Figure 6 The throttling sleeve 212 has an inner flange 2121 at the end away from the first valve body 11. The throttling port 2102 extends through the opposite two end faces 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.

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

[0075] In other words, the above structure can simply form a second oil inlet 2101, a throttling oil inlet 2102, and an unloading oil inlet 2103 in the second valve body 21.

[0076] In this embodiment, the valve sleeve 211 has internal threads at the end facing the first valve body 11, and the throttling sleeve 212 has external threads on its outer wall. The throttling sleeve 212 and the valve sleeve 211 are connected together by threads. This facilitates their assembly and disassembly. To further facilitate the threaded connection of the throttling sleeve 212 into the valve sleeve 211, the interior of the throttling sleeve 212 is hexagonal, making it easy to install the throttling sleeve 212 using a hexagonal wrench. The outer wall of the valve sleeve 211 has external threads, and the valve sleeve 211 is inserted into the mounting hole 1131 and connected by threads. Because the valve sleeve 211 and the throttling sleeve 212 are connected by threads, throttling sleeves 212 with different sizes of throttling ports 2102 can be selected according to different pressures and flow rates.

[0077] Multiple throttling ports 2102 are provided, and these ports are arranged at intervals along the circumference of the inner flange 2121 in the sidewall of the inner flange 2121. This provides a basis for the arrangement of the throttling ports 2102 within the inner flange 2121, allowing for a simple arrangement. In this embodiment, four throttling ports 2102 are provided, and these four ports are evenly distributed along the circumference of the inner flange 2121.

[0078] The inner flange 2121 can be integrally cast with the throttling sleeve 212, or it can be welded to the inner wall of the throttling sleeve 212. The throttling port 2102 is machined by rotary cutting of an involute profile, which facilitates the smooth flow of hydraulic oil.

[0079] See you again Figure 5 Optionally, the unloading 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 inside the valve sleeve 211 and at the end of the throttling sleeve 212 away from the first valve body 11. When the pressure at the second inlet 2101 is greater than the second threshold, the second valve core body 221 is spaced apart from the throttling sleeve 212, and a connecting channel is formed between the outer wall of the second valve core body 221 and the valve sleeve 211, connecting the unloading port 2103 and the second inlet 2101. When the pressure at the second inlet 2101 is not greater than the second threshold, 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 port 2103 is an annular cavity, and part of the unloading 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 throttling sleeve 212 has a first sealing slope 2210. The inner wall of the throttling sleeve 212 facing the second valve core body 221 has a second sealing slope 2120. When the pressure at the second oil inlet 2101 is not greater than the second threshold, the first sealing slope 2210 and the second sealing slope 2120 are in contact.

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

[0084] Figure 7 This is a schematic diagram of the structure of the second valve core body, combined with... Figure 7 In this embodiment, the second valve core body 221 is a rod-shaped structure, and includes a constricted section 2211 and a flared section 2212 connected to each other along the length 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 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 slides in contact with the inner wall of the valve sleeve 211. In this way, a connecting channel between the unloading port 2103 and the second inlet port 2101 can be formed between the constricted section 2211 with its smaller outer diameter and the inner wall of the valve sleeve 211. Meanwhile, by arranging the flared section 2212 on the side of the unloading port 2103 away from the throttle sleeve 212, the hydraulic oil can be unloaded preferentially from the unloading port 2103, and will not leak out from between the flared section 2212 and the valve sleeve 211.

[0085] The flared section 2212 has a spring cavity for mounting a second elastic element 223 (described below), one end of which extends to the end face of the flared section 2212 away from the constricted section 2211.

[0086] See you again Figure 5 Optionally, the second valve core assembly 22 further includes a second elastic element 223, which is located inside the valve sleeve 211 and on the side of the second valve core body 221 away from the throttling sleeve 212. The two ends of the second elastic element 223 abut against the valve sleeve 211 and the second valve core body 221, respectively.

[0087] In the above implementation, the arrangement of the second elastic element 223 allows the second valve core body 221 to automatically reset after movement, thereby isolating the second oil inlet 2101 and the unloading oil inlet 2103, and thus closing the back pressure valve unit 2 for reuse. At the same time, the movement of the second valve core body 221 is restricted, so that the second valve core body 221 can only move after overcoming the elastic force of the second elastic element 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, and the valve cover 2112 is located at the other end of the sleeve body 2111 and is movably connected to the other end of the sleeve body 2111 so that the valve cover 2112 can move relative to the sleeve body 2111 toward or away from the second elastic member 223.

[0089] The second spring seat 2113 is located inside the sleeve body 2111, with one end of the second spring seat 2113 contacting the valve cover 2112 and the other end inserted into the second elastic member 223, abutting against the end face of the second elastic member 223. The end of the second elastic member 223 facing the second valve core body 221 is inserted into the second valve core body 221.

[0090] In the above implementation, the sleeve body 2111 provides a mounting base for the second elastic element 223, the second valve core body 221, etc. The valve cover 2112 is movably connected to the sleeve body 2111 to apply different forces to the second spring seat 2113. The second spring seat 2113 abuts against the second elastic element 223 to adjust the set pressure of the second elastic element 223, thereby changing the magnitude of the second threshold, making the back pressure valve pressure adjustable and possessing strong impact resistance.

[0091] In this 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, into which a screw 2114 is inserted, and a nut 2115 is fitted over the screw. By adjusting the length of the screw 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 element 223.

[0092] Figure 8 This is a structural schematic diagram of the sleeve body, combined with... Figure 8Optionally, the sleeve body 2111 has a first positioning stop 201 and a second positioning stop 202 at its opposite ends. The first positioning stop 201 is arranged facing the first valve body 11, and the second positioning stop 202 is arranged away from the first valve body 11. The first positioning stop 201 is located on the side of the throttling sleeve 212 away from the first valve body 11. The first positioning stop 201 is used to engage the throttling sleeve 212. The inner wall of the sleeve body 2111 between the end face facing the first valve body 11 and the first positioning stop 201 has an internal thread. This allows the throttling sleeve 212 to be installed inside the sleeve body 2111 through the internal thread, while the first positioning stop 201 positions and engages the throttling sleeve 212 to prevent it from slipping 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 engages 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 working process of the back pressure valve provided in this embodiment is briefly described below:

[0094] Hydraulic oil from the pump outlet enters the first valve body 11 through the first inlet 1101, and then enters the outlet 1102 through the notch 1105 in the first valve core body 121. Part of the hydraulic oil in the outlet 1102 enters the second inlet 2101, and the other part enters the feedback port 1103. The hydraulic oil in the feedback port 1103 enters the feedback reservoir 1112 through the flow hole 1113, and the hydraulic oil in the feedback reservoir 1112 acts on the end face 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 reservoir 1112 increases accordingly. When the pressure of the hydraulic oil in the feedback oil reservoir 1112 is high enough to push the first valve core body 121 to move to the right against the elastic force of the first elastic element 123, the flow area of ​​the flow passage 1104 decreases, and the pressure of the hydraulic oil at the oil outlet 1102 decreases to achieve pressure reduction.

[0096] After pressure reduction, the hydraulic oil re-enters the second inlet 2101. At this time, under the elastic force of the second elastic element 223, the second valve core body 221 closes the second inlet 2101, allowing the hydraulic oil to only pass through the throttling port 2102 and reach the unloading port 2103 for discharge. When the flow rate of hydraulic oil in the second inlet 2101 is large, a significant pressure loss will occur at the throttling port 2102. When the pressure loss increases to exceed the pressure set by the second elastic element 223, the second valve core body 221 moves. The second valve core body 221 and the throttling sleeve 212 form a connecting channel between the second inlet 2101 and the unloading port 2103. The hydraulic oil directly enters the unloading port 2103 from the second inlet 2101, greatly increasing the effective flow area of ​​the hydraulic oil, reducing the pressure drop, thereby reducing the pump outlet pressure and reducing energy loss.

[0097] The back pressure valve provided in this embodiment can be directly connected to the pump outlet without the need for pipeline connection, reducing the hydraulic oil resistance in the pipeline and thus saving energy. Therefore, this back pressure valve can effectively reduce the energy loss of the hydraulic pump, reduce system heat generation, and save energy and protect the environment. Furthermore, the back pressure valve is integrated through a pressure reducing valve unit 1 and a back pressure valve unit 2, making it compact and easy to install. Simultaneously, because the pressure reducing valve unit 1 has a feedback port 1103, the back pressure valve has a feedback regulation function, making the back pressure valve movement more stable and reducing vibration.

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

Claims

1. A back pressure valve, characterized in that, 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 outlet (1103). The oil outlet (1102) is connected to the first oil inlet (1101) and the feedback oil outlet (1103) respectively. The first valve core assembly (12) is movably located within the first valve body (11). The first valve core assembly (12) includes a first valve core body (121), which is movably located within the first valve body (11). One end of the first valve core body (121) faces the feedback port (1103). The first valve core body (121) includes a valve stem (1211) and a first outer flange (1212) disposed on the outer wall of the middle portion of the valve stem (1211). The outer wall of the first outer flange (1212) slides in contact with the inner wall of the first valve body (11). The first outer flange (1212) is located between the first inlet port (1101) and the outlet port (1102). The pressure at the feedback port (1103) is not greater than a first threshold value. At that time, a flow passage (1104) is formed between the first outer flange (1212) and the inner wall of the first valve body (11) to connect 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, the flow area of ​​the flow passage (1104) gradually decreases. The outer wall of the first outer flange (1212) facing the oil outlet (1102) has a plurality of notches (1105). The plurality of notches (1105) are arranged at intervals along the circumference of the first outer flange (1212), and each of the plurality of notches (1105) extends from the end of the first outer flange (1212) facing the oil outlet (1102) to the outer wall of the first outer flange (1212). The back pressure valve unit (2) includes 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 inlet (2102), and an unloading oil inlet (2103). The second oil inlet (2101) is connected to the oil outlet (1102). The two ends of the throttling oil inlet (2102) are connected to the second oil inlet (2101) and the unloading oil inlet (2103) respectively. The flow area of ​​the unloading oil inlet (2103) is larger than that of the throttling oil inlet (2102), and the unloading oil inlet (2103) is connected to the oil tank. The second valve body (21) includes a valve sleeve (211) and a... A throttling sleeve (212) is provided. 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 the end of the valve sleeve (211) facing the first valve body (11). The throttling sleeve (212) is connected to the valve sleeve (211). The inner wall of the end of the throttling sleeve (212) away from the first valve body (11) has an inner flange (2121). The throttling oil port (2102) extends along the axis of the inner flange (2121) through the opposite end faces of the inner flange (2121). The inner hole of the inner flange (2121) defines the second oil inlet (2101). 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: connect the second oil inlet (2101) and the unloading oil port (2103) when the pressure at the second oil inlet (2101) is greater than the second threshold, and disconnect the second oil inlet (2101) from the unloading oil port (2103) when the pressure at the second oil inlet (2101) is not greater than the second threshold, wherein the second threshold is greater than the first threshold.

2. The back pressure valve according to claim 1, characterized in that, The first valve core assembly (12) further includes a first spring seat (122) and a first elastic element (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 first elastic element (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 element (123) abut against the inner walls of the first spring seat (122) and the first valve body (11), respectively.

3. The back pressure valve according to claim 2, characterized in that, 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 located on opposite sides of the valve block (113), and the first end plate (111) and the second end plate (112) are connected to the valve block (113). The first end plate (111) has a first protrusion (1111) on one side facing the second end plate (112). The first protrusion (1111) is located inside the valve block (113) and is used to contact one end of the first valve core body (121). The second end plate (112) has a second protrusion (1121) on one side 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).

4. The back pressure valve according to claim 3, characterized in that, The first protrusion (1111) has a feedback oil storage chamber (1112) inside, the feedback oil storage chamber (1112) is arranged along the length direction of the first protrusion (1111) and extends to one end face of the first protrusion (1111) facing the first valve core assembly (12); The sidewall 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).

5. The back pressure valve according to claim 1, characterized in that, The unloading 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 inside the valve sleeve (211) and at one 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 the second threshold, the second valve core body (221) is spaced apart from the throttling sleeve (212). A connecting channel is formed between the outer wall of the second valve core body (221) and the valve sleeve (211) connecting the unloading oil port (2103) and the second oil inlet (2101). When the pressure at the second oil inlet (2101) is not greater than the second threshold, the second valve core body (221) blocks the inner hole of the inner flange (2121).

6. The back pressure valve according to claim 5, characterized in that, The second valve core body (221) has a first sealing slope (2210) on the outer wall of the end facing the throttling sleeve (212); The throttling sleeve (212) has a second sealing slope (2120) on the inner wall of one end facing the second valve core body (221). When the pressure at the second oil inlet (2101) is not greater than the second threshold, the first sealing slope (2210) and the second sealing slope (2120) fit together.

7. The back pressure valve according to claim 5, characterized in that, The second valve core assembly (22) further includes a second elastic element (223), which is located inside the valve sleeve (211) and on the side of the second valve core body (221) away from the throttling sleeve (212). The two ends of the second elastic element (223) abut against the valve sleeve (211) and the second valve core body (221) respectively.

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