Hydraulic tool

Abstract

The invention belongs to the technical field of hydraulic systems, and particularly relates to a hydraulic tool which comprises an automatic pressure relief valve, and the automatic pressure relief valve comprises a pressure relief valve body, a valve element mounting cavity and a valve element mounting cavity. The pressure relief valve seat is provided with a valve seat connecting part used for being connected with the pressure relief valve body and a valve seat fixing part used for stretching out of the outer side of the pressure relief valve body, and the pressure relief valve seat is further provided with a valve seat channel communicating with the pressure relief channel and the valve element mounting cavity; and the pressure relief valve element assembly is mounted in the valve element mounting cavity and used for controlling opening and closing of the valve seat channel. The pressure relief valve body is directly fixed to the liquid outlet end of the pressure relief channel through the pressure relief valve seat, and compared with the prior art, a threaded connection structure at the pressure relief valve body is omitted, so that the risk that the pressure relief valve body is deformed and broken due to external force is reduced, and the mounting stability of the pressure relief valve element assembly and the sealing stability of the valve seat channel are improved; and meanwhile, the pressure relief valve body is more convenient to machine and install, and the overall production cost and assembly difficulty can be better reduced.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic system technology, and specifically relates to a hydraulic tool. Background Technology

[0002] A pressure relief valve (also known as a safety valve) is a valve that can automatically open and close according to system pressure. It is widely used in hydraulic systems, especially in the field of hydraulic tools.

[0003] The invention patent with authorization announcement number CN107542637B discloses a safety valve, which includes a safety valve body connected to a pump body via threads. Inside the safety valve body, a safety valve seat, a valve core, a safety valve stem, a valve core spring, and a sliding sleeve are arranged sequentially. The safety valve seat has a pressure relief hole in the middle and is threaded into the safety valve body. One end of the safety valve stem passes through the safety valve spring seat, and the other end connects to the valve core. A sliding sleeve is fitted onto the safety valve stem and contacts the valve core. The valve core spring is sleeved on the outer circumference of the safety valve stem, located between the safety valve spring seat and the sliding sleeve. Under the action of the valve core spring, the sliding sleeve presses against the valve core, enabling the valve core to seal the pressure relief hole of the safety valve seat.

[0004] The existing technical solution has the following problems: 1. Installation may lead to deformation: The safety valve body and pump body are connected by threads. However, the side wall of the safety valve body is relatively thin. When tightening with tools, the pressure exerted by the tools on the side wall of the safety valve body can easily cause deformation, making it impossible to properly install internal components such as the valve core, safety valve stem, valve core spring, and sliding sleeve. Even if assembly is completed, it may affect the sealing stability of the valve core to the pressure relief hole.

[0005] 2. Complex assembly process: Both the safety valve seat and the safety valve body require tools for threaded installation, making the assembly process cumbersome and increasing the overall assembly difficulty and production cost. Summary of the Invention

[0006] The purpose of this invention is to provide a hydraulic tool that is simple in structure and easy to install.

[0007] The present invention adopts the following technical solution: A hydraulic tool includes: a cylinder body with an inlet channel and a pressure relief channel, wherein an inlet check valve, a plunger assembly, and an outlet check valve are sequentially arranged on the inlet channel; a clamp head mounting seat, installed at the front end of the cylinder body, forming a piston chamber therebetween the cylinder body, the piston chamber being connected to the outlet end of the inlet channel and the inlet end of the pressure relief channel; an oil bag, installed at the rear end of the cylinder body, and connected to the inlet end of the inlet channel and the outlet end of the pressure relief channel; and an automatic pressure relief valve, installed at the outlet end of the pressure relief channel, for realizing the automatic pressure relief of the piston chamber. Automatic pressure relief; wherein the automatic pressure relief valve includes: a pressure relief valve body having a valve core mounting cavity; a pressure relief valve seat having a valve seat connecting part for connecting with the pressure relief valve body and a valve seat fixing part for extending outward of the pressure relief valve body, the valve seat fixing part being able to be fixed on the pressure relief channel, the pressure relief valve seat also having a valve seat channel communicating with the pressure relief channel and the valve core mounting cavity; and a pressure relief valve core assembly, installed in the valve core mounting cavity and used to control the opening and closing of the valve seat channel; wherein the pressure relief valve seat is able to fix the pressure relief valve body at the liquid outlet end of the pressure relief channel.

[0008] Preferably, the mounting end of the pressure relief valve body has a valve seat mounting hole, and the inner side of the valve seat mounting hole has a limiting step; the valve seat connection part has a limiting flange that matches the limiting step.

[0009] Preferably, the valve seat fixing part is an externally threaded part; the diameter of the valve seat connecting part is larger than the diameter of the valve seat fixing part, and a sealing gasket is fitted on the valve seat fixing part.

[0010] Preferably, the pressure relief valve core assembly comprises: a pressure relief pin with a pin sealing portion for sealing the valve seat passage; a pressure relief piston fitted on the pressure relief pin; a pressure relief spring fitted on the pressure relief pin; and a spring adjusting seat threadedly fixed to the adjusting end of the pressure relief valve body; wherein the pressure relief spring abuts against the pressure relief piston and the spring adjusting seat, and is used to drive the pressure relief pin to seal the valve seat passage through the pressure relief piston; wherein the pressure relief valve body has at least one first pressure relief hole and a second pressure relief hole communicating with the valve core mounting cavity, the first pressure relief hole communicating with the space between the pressure relief piston and the pressure relief valve seat; and the second pressure relief hole communicating with the space between the pressure relief piston and the spring adjusting seat.

[0011] Preferably, the outlet end of the pressure relief channel is provided with an internal threaded hole for mounting to the pressure relief valve seat and a groove-shaped limiting part for restricting the rotation of the pressure relief valve body; an irregular limiting wall is provided on the outer side of the mounting end of the pressure relief valve body to prevent the pressure relief valve body from rotating.

[0012] Preferably, the device further includes a manual pressure relief valve disposed on the pressure relief channel, comprising: a valve mounting seat with a pressure relief valve hole; a valve ball that seals the pressure relief valve hole by a first spring; a valve push rod disposed on the outside of the valve mounting seat by a second spring, the outer end of the valve push rod extending out of the cylinder body, and its inner end capable of passing through the pressure relief valve hole to press the valve ball; and a pressing handle rotatably disposed on the cylinder body, pressing the pressing handle causing the valve push rod and valve ball to move and open the pressure relief valve hole, thereby realizing manual pressure relief.

[0013] Preferably, a movable handle for driving the piston assembly is hinged to the cylinder body, and a handle locking mechanism is provided between the movable handle and the cylinder body; the handle locking mechanism includes: a limiting plate fixed to the cylinder body; a locking hook movably disposed on the movable handle and having a locked position and an unlocked position; a reset member for driving the locking hook closer to the limiting plate; and a switch locking pin for controlling the locking hook to be in the locked position or the unlocked position; in the locked position, the locking hook can engage with the limiting plate, thereby locking the movable handle; in the unlocked position, the locking hook and the limiting plate do not interfere with each other on the path of the movable handle.

[0014] Preferably, the locking hook has: a rotating part rotatably disposed on the movable handle; a hook part disposed on one side of the rotating part for engaging with the limiting plate; and a limiting part abutting against the switch locking pin.

[0015] Preferably, the switch locking pin is rotatably mounted on the movable handle, and a manual knob is provided at the outer end; The switch locking pin has an eccentric structure in the middle for abutting the limiting part. The position of the locking hook can be changed by rotating the eccentric structure. The eccentric structure includes a locking eccentric groove on one side of the switch locking pin and / or an unlocking eccentric groove on the other side of the switch locking pin. In the locked position, the limiting part of the locking hook abuts against the bottom plane of the locking eccentric groove. In the unlocked position, the limiting part of the locking hook abuts against the bottom plane of the unlocking eccentric groove.

[0016] Preferably, the cylinder body is made of lightweight metal material, and the limiting plate is made of high-strength material.

[0017] The outstanding and beneficial technical effects of this invention compared to the prior art are: 1. The pressure relief valve body of the present invention is directly fixed to the liquid outlet end of the pressure relief channel through the pressure relief valve seat. Compared with the prior art, it reduces one threaded connection structure at the pressure relief valve body, thereby reducing the risk of deformation and breakage of the pressure relief valve body under external force, and improving the installation stability of the pressure relief valve core assembly and the sealing stability of the valve seat channel. At the same time, the pressure relief valve body is easier to process and install, and can further reduce the overall production cost and assembly difficulty.

[0018] 2. One end of the pressure relief valve seat of the present invention is provided with an external thread for easy thread fixing; the other end is provided with an annular flange, which has greater strength and is not easy to break, and also has a certain end face sealing effect.

[0019] 3. The cylinder body and the limiting plate of the present invention are set separately, which can reduce the strength requirements of the cylinder body. The cylinder body can preferably be made of lightweight aluminum, while the limiting plate can be made of stronger metal materials such as cast iron or other high-strength composite materials, thereby reducing the overall weight of the hydraulic tool and ensuring its service life. At the same time, if the limiting plate fails, only the limiting plate needs to be replaced, without replacing the cylinder body, which greatly reduces maintenance costs and maintenance difficulty.

[0020] 4. The switch locking pin of the present invention has an eccentric structure in the middle for abutting the limiting part. The position of the locking hook can be changed by rotating the eccentric structure, which has the advantage of simple operation. At the same time, under the action of the reset member, the limiting part abuts against the bottom plane of the groove, which can prevent the switch locking pin from rotating arbitrarily and achieve self-positioning. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the hydraulic tool of the present invention.

[0022] Figure 2 This is one of the cross-sectional views of the hydraulic tool of the present invention.

[0023] Figure 3 This is a second cross-sectional view of the hydraulic tool of the present invention.

[0024] Figure 4 This is a schematic diagram of the cylinder body and automatic pressure relief valve of the present invention.

[0025] Figure 5 This is a schematic diagram of the rear end of the cylinder block of the present invention.

[0026] Figure 6 This is a schematic diagram of the automatic pressure relief valve of the present invention.

[0027] Figure 7 This is a cross-sectional view of the installation location of the automatic pressure relief valve of the present invention.

[0028] Figure 8 This is one of the exploded views of the automatic pressure relief valve of the present invention.

[0029] Figure 9 This is the second exploded view of the automatic pressure relief valve of the present invention.

[0030] Figure 10 yes Figure 2 A partial schematic diagram of the handle locking mechanism at point A in the locked state.

[0031] Figure 11This is a partial structural diagram of the movable handle of the present invention.

[0032] Figure 12 This is a partial schematic diagram of the handle locking mechanism of the present invention in the unlocked state.

[0033] Figure 13 This is a cross-sectional view of the handle locking mechanism of the present invention.

[0034] Figure 14 This is an exploded view of the handle locking mechanism of the present invention.

[0035] The meaning of the labels in the diagram: 1. Cylinder body; 2. Automatic pressure relief valve; 3. Inlet check valve; 4. Plunger assembly; 5. Outlet check valve; 6. Pliers mounting base; 7. Manual pressure relief valve; 8. Movable handle; 9. Handle locking mechanism; 10. Fixed handle; Liquid inlet channel 11; pressure relief channel 12; groove-shaped limiting part 121; manual pressure relief hole 122; automatic pressure relief hole 123; piston chamber 13; oil bag 14; piston assembly 15; filter 16; Pressure relief valve body 21; valve seat mounting hole 211; limiting step 212; first pressure relief hole 213; second pressure relief hole 214; irregular limiting wall 215; pressure relief valve seat 22; valve seat connecting part 221; limiting flange 2211; auxiliary tool insertion part 2212; valve seat fixing part 222; valve seat channel 223; first sealing ring 23; sealing gasket 24; pressure relief pin 25; pin sealing part 251; pressure relief spring 26; spring pressure adjusting seat 27; pressure relief piston 28; annular groove 281; connecting hole 282; gasket 29; second sealing ring 30; First spring 71; valve ball 72; valve mounting seat 73; valve rod 74; second spring 75; pressing handle 76; handle pressing part 761; handle limiting part 762; Limiting plate 91; limiting hole 911; limiting protrusion 912; limiting screw 913; locking hook 92; rotating part 921; hook part 922; limiting part 923; torsion spring mounting part 924; reset part 93; switch locking pin 94; manual knob 941; locking eccentric groove 942; unlocking eccentric groove 943; rotating pin 95. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments: like Figure 1 , 2 As shown in Figures 1 and 3, a hydraulic tool includes a cylinder body 1, a clamp head mounting seat 6, an oil bag 14, an automatic pressure relief valve 2, an inlet check valve 3, a plunger assembly 4, an outlet check valve 5, and a manual pressure relief valve 7.

[0037] The cylinder body 1 is provided with an inlet channel 11 and a pressure relief channel 12. A pliers head mounting seat 6 is installed at the front end of the cylinder body 1. The pliers head mounting seat 6 is used to install different types of pliers heads, such as scissor pliers heads, crimping pliers heads, punching pliers heads, clamp pliers heads, etc. A piston chamber 13 is formed between the pliers head mounting seat 6 and the cylinder body 1. An oil bag 14 is installed at the rear end of the cylinder body 1. The oil bag 14 is filled with hydraulic oil. The inlet channel 11 and the pressure relief channel 12 are respectively connected to the oil bag 14 and the piston chamber 13. An inlet check valve 3, a plunger assembly 4, and an outlet check valve 5 are sequentially arranged on the inlet channel 11. A manual pressure relief valve 7 and an automatic pressure relief valve 2 are arranged on the pressure relief channel 12.

[0038] Specifically, the inlet end of the liquid inlet channel 11 is equipped with an inlet check valve 3 and a filter 16; a plunger chamber is provided in the middle of the liquid inlet channel 11, and a plunger assembly 4 is installed in the plunger chamber. The plunger assembly 4 achieves reciprocating motion through a drive unit, which can be an electric drive unit or a manual drive unit; an outlet check valve 5 is installed at the outlet end of the liquid inlet channel 11.

[0039] In this embodiment, a piston assembly 15 and an execution unit for driving the pliers head are installed in the piston chamber 13. The piston assembly 15 mainly includes a piston, a piston rod, a piston return spring, and other structures. The execution unit is a roller seat and a double roller structure. The structures of the piston assembly 15 and the execution unit are existing technologies and will not be described in detail here.

[0040] When the drive unit is working, it drives the plunger assembly 4 to move. The hydraulic oil in the oil bag 14 enters the piston chamber 13 sequentially through the inlet check valve 3, the plunger chamber, and the outlet check valve 5. As the hydraulic oil increases, the piston assembly 15 and the actuator in the piston chamber 13 extend outward, thereby driving the clamp head to perform the corresponding function. When the pressure in the piston chamber 13 exceeds the threshold of the automatic pressure relief valve 2, the automatic pressure relief valve opens, and part or all of the hydraulic oil in the piston chamber 13 can flow back into the oil bag 14 through the pressure relief channel 12, realizing automatic pressure relief of the piston chamber 13. When the clamp head finishes working, the user manually opens the manual pressure relief valve 7, and under the action of the piston return spring of the piston assembly 15, all the hydraulic oil in the piston chamber 13 can flow back into the oil bag 14.

[0041] like Figure 4 , 5 As shown, the automatic pressure relief valve 2 is installed at the liquid outlet end of the pressure relief channel 12. Specifically, the liquid outlet end of the pressure relief channel 12 is provided with a manual pressure relief hole 122 for discharging liquid from the manual pressure relief valve 7 and an automatic pressure relief hole 123 for installing the automatic pressure relief valve 2. In this embodiment, the automatic pressure relief hole 123 is an internally threaded hole.

[0042] like Figure 6-9 As shown, the automatic pressure relief valve 2 includes a pressure relief valve body 21, a pressure relief valve seat 22, and a pressure relief valve core assembly.

[0043] Specifically, the pressure relief valve body 21 has a valve core mounting cavity. A pressure relief valve seat 22 and a pressure relief valve core assembly are mounted at one end of the valve core mounting cavity. The pressure relief valve seat 22 has a valve seat connecting portion 221 for connecting to the pressure relief valve body 21 and a valve seat fixing portion 222 for extending outwards from the outside of the pressure relief valve body 21. The valve seat fixing portion 222 can be fixed to the pressure relief channel 12. Simultaneously, the pressure relief valve seat 22 also has a valve seat channel 223 communicating with the pressure relief channel 12 and the valve core mounting cavity. The pressure relief valve core assembly is used to control the opening and closing of the valve seat channel 223.

[0044] Preferably, the valve seat fixing part 222 in this embodiment is an external threaded part, and can be threaded into the automatic pressure relief hole 123, so that the pressure relief valve seat 22 can fix the pressure relief valve body 21 to the liquid outlet end of the pressure relief channel 12.

[0045] In this embodiment, the pressure relief valve body 21 is directly fixed to the liquid outlet end of the pressure relief channel 12 via the pressure relief valve seat 22. Compared with the prior art, this reduces the number of threaded connection structures at the pressure relief valve body 21, thereby reducing the risk of deformation and breakage of the pressure relief valve body 21 under external forces and improving the installation stability of the pressure relief valve core assembly and the sealing stability of the valve seat channel 223. At the same time, the pressure relief valve body 21 is easier to process and install, which can further reduce the overall production cost and assembly difficulty.

[0046] In other embodiments, the valve seat fixing part 222 may also be a snap-fit ​​part, a welded part, or other means of being fixedly connected to the pressure relief channel 12.

[0047] Preferably, such as Figure 7 As shown, the mounting end of the pressure relief valve body 21 has a valve seat mounting hole 211 communicating with the valve core mounting cavity. The valve seat mounting hole 211 is a through hole, and the inner diameter of the through hole is smaller than the inner diameter of the valve core mounting cavity, so that the inner side of the valve seat mounting hole 211 has an annular limiting step 212. The outer diameter of the main body of the valve seat connecting part 221 is adapted to the inner diameter of the valve seat mounting hole 211. A first sealing ring 23 is provided between the valve seat connecting part 221 and the inner wall of the valve seat mounting hole 211 to increase the sealing performance of both. In addition, the inner end of the valve seat connecting part 221 has a limiting flange 2211 adapted to the limiting step 212. The limiting flange 2211 can be an annular flange or several evenly distributed flange protrusions, used to cooperate with the limiting step 212 to achieve the limiting function. In this embodiment, an annular flange is preferred, which has greater strength, is not easy to break, and also has a certain end face sealing effect. In another embodiment, a gasket can be provided between the limiting flange 2211 and the limiting step 212 to increase their sealing performance.

[0048] In this embodiment, the diameter of the valve seat connecting part 221 is larger than the diameter of the valve seat fixing part 222. A sealing gasket 24 is fitted on the valve seat fixing part 222. The sealing gasket 24 is located on the outer end face of the valve seat connecting part 221 and the mounting surface of the cylinder body 1, further ensuring the seal at the valve seat fixing part 222. Preferably, in this embodiment, the outer end of the automatic pressure relief hole 123 is also provided with a groove that matches the shape of the sealing gasket 24, and the mounting surface of the cylinder body 1 is the bottom surface of the groove.

[0049] In another embodiment, the outer end of the valve seat connection 221 can also extend out of the valve seat mounting hole 211, and the sealing gasket 24 is fitted on the valve seat connection 221 and located on the mounting end face of the pressure relief valve body 21 and the mounting surface of the cylinder body 1.

[0050] To facilitate the rotation of the pressure relief valve seat 22, an auxiliary tool insertion part 2212 for driving the rotation of the pressure relief valve seat 22 is provided at the outer end of the valve seat connecting part 221 away from the valve seat fixing part 222. The auxiliary tool insertion part 2212 can be a polygonal hole or a polygonal boss, or multiple insertion holes, which can be used to achieve rotation using conventional or specific tools. In this embodiment, the auxiliary tool insertion part 2212 is located on the end face of the side where the limiting flange 2211 is located.

[0051] like Figure 7 As shown, the outlet end of the valve seat channel 223 of the pressure relief valve seat 22 is formed with a pressure relief hole, and the inner diameter of the pressure relief hole is smaller than the inner diameter of the valve seat channel 223.

[0052] The pressure relief valve core assembly includes a pressure relief pin 25, a pressure relief spring 26, and a spring adjusting seat 27.

[0053] The pressure relief pin 25 has a pin sealing part 251 that blocks the valve seat passage 223 and an annular abutment part. The pin sealing part 251 has a conical structure and is used to act on the pressure relief orifice to achieve the sealing and opening of the pressure relief orifice. The annular abutment part is provided at one end of the pressure relief pin 25 near the pin sealing part 251. A pressure relief spring 26 and a spring adjusting seat 27 are fitted onto the pressure relief pin 25. The spring adjusting seat 27 is threadedly fixed to the adjusting end of the pressure relief valve body 21. The adjusting end of the pressure relief valve body 21 is provided with an internal thread. The pressure relief spring 26 abuts against the annular abutment part of the pressure relief pin 25 and the spring adjusting seat 27. Under the action of the pressure relief spring 26, the pressure relief pin 25 seals the pressure relief hole of the valve seat channel 223. When the pressure in the pressure relief channel 12 is greater than the force of the pressure relief spring 26, the pressure relief pin 25 is pushed open, and the hydraulic oil can flow back into the oil bag 14 through the pressure relief hole of the pressure relief valve body 21 or the gap between the pressure relief valve core assembly, thereby achieving automatic pressure relief.

[0054] In another embodiment, the pressure relief valve core assembly also has a pressure relief piston 28, the outer side of which is adapted to the inner wall of the valve core mounting cavity and is located between the pressure relief pin 25 and the pressure relief spring 26.

[0055] Specifically, a pressure relief piston 28, a pressure relief spring 26, and a spring adjusting seat 27 are sequentially mounted on the pressure relief pin 25. The pressure relief piston 28 abuts against one side of the annular abutment part, and the pressure relief spring 26 abuts against the pressure relief pin 25 through the pressure relief piston 28.

[0056] Preferably, at least one pressure relief hole is provided on the side wall of the pressure relief valve body 21. In this embodiment, at least one first pressure relief hole 213 and a second pressure relief hole 214 are provided on the pressure relief valve body 21 to connect the valve core mounting cavity. The first pressure relief hole 213 can connect the space between the pressure relief piston 28 and the pressure relief valve seat 22; the second pressure relief hole 214 can connect the space between the pressure relief piston 28 and the spring pressure adjusting seat 27.

[0057] The side wall of the pressure relief piston 28 is provided with an annular groove 281 that connects the first pressure relief hole 213 and / or the second pressure relief hole 214, and at least one connecting hole 282 that connects the annular groove 281. The connecting hole 282 connects the space between the pressure relief piston 28 and the pressure relief valve seat 22. When the valve seat channel 223 is opened, the valve seat channel 223, the connecting hole 282, the annular groove 281, and the first pressure relief hole 213 or the second pressure relief hole 214 are connected in sequence.

[0058] Specifically, when the pressure in the valve seat passage 223 is greater than the force of the pressure relief spring 26, the pressure relief pin 25 drives the pressure relief piston 28 to move outward and opens the valve seat passage 223. The hydraulic oil originally between the pressure relief piston 28 and the spring pressure adjusting seat 27 can be quickly discharged through the second pressure relief hole 214 to achieve rapid outward movement of the pressure relief piston 28. After the pressure relief piston 28 moves outward a certain distance, the hydraulic oil in the valve seat passage 223 can flow back to the oil bag 14 through the first pressure relief hole 213. If the movement distance is far enough, the hydraulic oil in the valve seat passage 223 can also flow back to the oil bag 14 through the connecting hole 282, the annular groove 281, and the second pressure relief hole 214 to accelerate the return speed.

[0059] When the pressure in the valve seat passage 223 is less than the force of the pressure relief spring 26, the pressure relief spring 26 resets, causing the pressure relief piston 28 and the pressure relief pin 25 to move towards the valve seat passage 223. Along the movement path of the pressure relief piston 28, the return area connecting the annular groove 281 and the second pressure relief hole 214 gradually decreases. The sidewall of the pressure relief piston 28 gradually covers the first pressure relief hole 213, further reducing the return area of ​​the first pressure relief hole 213 and thus slowing down the movement speed of the pressure relief piston 28. This allows the pressure relief pin 25 to delay sealing the valve seat passage 223. Finally, the hydraulic oil between the pressure relief piston 28 and the pressure relief valve seat 22 flows back into the oil bag 14 through the connecting hole 282, the annular groove 281, and the first pressure relief hole 213, thereby sealing the pressure relief orifice. During the delayed closing process of the pressure relief pin 25, the low-pressure hydraulic oil in the piston chamber 13 can also quickly flow back into the oil bag 14, accelerating the reset of the piston assembly 15.

[0060] Preferably, a gasket 29 and a second sealing ring 30 are provided between the pressure relief pin 25 and the spring pressure adjusting seat 27. One end face of the gasket 29 abuts against the inner wall of the spring pressure adjusting seat 27 to limit the axial position of the second sealing ring 30, and its other end face abuts against the pressure relief spring 26.

[0061] To prevent the pressure relief valve body 21 from rotating axially, a groove-shaped limiting part 121 is provided at the liquid outlet end of the pressure relief channel 12 to restrict the rotation of the pressure relief valve body 21. The groove-shaped limiting part 121 is a polygonal groove such as a square groove or a circular groove with at least one flat surface (such as a D-shaped groove or a racetrack-shaped groove). An irregular limiting wall 215 is provided on the outer side of the mounting end of the pressure relief valve body 21, which is at least one flat surface formed on the cylindrical side wall and can just contact the inner wall plane of the groove-shaped limiting part 121, thereby preventing the pressure relief valve body 21 from rotating.

[0062] like Figure 3 As shown, the manual pressure relief valve 7 includes a first spring 71, a valve ball 72, a valve mounting seat 73, a valve rod 74, a second spring 75, and a pressing handle 76.

[0063] The valve mounting base 73 has a pressure relief valve hole, and a first spring 71 and a valve ball 72 are mounted on the liquid inlet channel 11. The valve ball 72 seals the pressure relief valve hole through the first spring 71. The valve push rod 74 is disposed on the outside of the valve mounting base 73 through a second spring 75. The valve push rod 74 is movably disposed with the cylinder body 1 through a sealing ring, and its outer end extends out of the cylinder body 1. Its inner end can pass through the pressure relief valve hole to press the valve ball 72. The inner diameter of the valve push rod 74 is smaller than the inner diameter of the pressure relief valve hole. The pressing handle 76 is rotatably disposed on the cylinder body 1 and has a handle pressing part 761 and a handle limiting part 762. Under the action of the second spring 75, the outer end of the valve push rod 74 abuts against the middle of the pressing handle 76 and maintains a relative position with the cylinder body 1 through the handle limiting part 762. The liquid outlet end of the pressure relief channel 12 also includes a manual pressure relief hole 122 disposed on the outside of the valve mounting base 73. When manual pressure relief is required, pressing the handle 76 moves the valve rod 74 and the valve ball 72 and opens the pressure relief valve hole. The hydraulic oil in the piston chamber 13 flows back into the oil bag 14 through the pressure relief valve hole and the manual pressure relief hole 122 of the pressure relief channel 12, thus achieving manual pressure relief.

[0064] Preferably, the hydraulic tool in this embodiment is a manual hydraulic tool, that is, the drive unit is a manual drive unit.

[0065] like Figure 2 As shown, the manual drive unit includes a fixed handle 10 fixed to the rear end of the cylinder 1 and a movable handle 8 hinged to the cylinder 1. The fixed handle 10 is fitted onto the outside of the oil bag 14. The movable handle 8 is a U-shaped metal piece used to drive the plunger assembly 4 to reciprocate. The plunger assembly 4 is prior art and will not be described in detail here. In addition, protective sleeves are provided at the outer ends of the fixed handle 10 and the movable handle 8.

[0066] A handle locking mechanism 9 is provided between the movable handle 8 and the cylinder 1 to lock the position between the movable handle 8 and the fixed handle 10, making it convenient to carry or transport.

[0067] like Figure 10-12 As shown, the handle locking mechanism 9 includes a limiting plate 91 and a locking hook 92.

[0068] The limiting plate 91 is fixed on the cylinder body 1 and located on one side of the plunger assembly 4. The locking hook 92 is movably disposed on the movable handle 8 and has a locked position and an unlocked position. In the locked position, the locking hook 92 can engage with the limiting plate 91, thereby locking the movable handle 8. In the unlocked position, the locking hook 92 and the limiting plate 91 do not interfere with each other on the path of the movable handle 8. This ensures that the movable handle 8 will not be engaged when driving the plunger assembly 4 to move, thereby ensuring that the movable handle 8 is normally reset under the action of the plunger assembly 4.

[0069] Preferably, a limiting hole 911 is provided in the middle of the limiting plate 91, and it is fixed in the threaded hole of the cylinder body 1 by a limiting screw 913. One end of the limiting plate 91 extends out of the cylinder body 1 and forms a locking part that cooperates with the locking hook 92; a limiting protrusion 912 and a limiting protrusion groove are respectively provided between the other end of the limiting plate 91 and the cylinder body 1 to limit the circumferential position of the limiting plate 91.

[0070] In another embodiment, such as Figure 11 As shown, the handle locking mechanism 9 also includes a reset member 93 and a switch locking pin 94. The reset member 93 is used to drive the locking hook 92 closer to the limit plate 91, and the switch locking pin 94 is used to control the locking hook 92 to be in the locked or unlocked position.

[0071] like Figure 12 As shown, the locking hook 92 has a rotating part 921 rotatably mounted on the movable handle 8, a hook part 922 mounted on one side of the rotating part 921, and a limiting part 923 abutting against the switch locking pin 94. The hook part 922 is used to engage with the limiting plate 91, and the rotating part 921 is movably mounted on the movable handle 8 via a rotating pin 95.

[0072] A switch locking pin 94 is also rotatably mounted on the movable handle 8 on one side of the rotating part 921. One end of the switch locking pin 94 is integrally formed with a manual knob 941. In addition, one end of the switch locking pin 94 is also provided with a limiting step. The other end of the switch locking pin 94 passes through the mounting hole of the movable handle 8 and is axially fixed by a snap ring.

[0073] The switch locking pin 94 has an eccentric structure in the middle for abutting the limiting part 923. The position of the locking hook 92 can be changed by rotating the eccentric structure, which has the advantage of simple operation.

[0074] Specifically, the eccentric structure includes a locking eccentric groove 942 disposed on one side of the switch locking pin 94, and / or an unlocking eccentric groove 943 disposed on the other side of the switch locking pin 94. The depth of the locking eccentric groove 942 is greater than the depth of the unlocking eccentric groove 943. Relative to the rotation axis of the switch locking pin 94, the bottom plane of the locking eccentric groove 942 is closer to the rotation axis, that is, the bottom plane of the unlocking eccentric groove 943 is farther away from the rotation axis.

[0075] like Figure 10As shown, in the locked position, the limiting part 923 of the locking hook 92 abuts against the bottom plane of the locking eccentric groove 942. Since the bottom plane of the locking eccentric groove 942 is closer to the rotation axis, the hook part 922 can get closer to the engaging part of the limiting plate 91. At this time, when the movable handle 8 approaches the cylinder body 1, the hook part 922 of the locking hook 92 interferes with the engaging part of the limiting plate 91, and the locking hook 92 can automatically engage with the limiting plate 91 to achieve locking. At the same time, under the action of the reset member 93, the limiting part 923 abuts against the bottom plane of the groove, which can prevent the switch locking pin 94 from rotating arbitrarily and achieve self-positioning.

[0076] Preferably, the hook portion 922 and / or the engaging portion of the limiting plate 91 are provided with guide slopes, which can guide the locking hook 92 to rotate and make room when the two come into contact, thereby achieving automatic engagement.

[0077] like Figure 12 As shown, in the unlocked position, the limiting part 923 of the locking hook 92 abuts against the bottom plane of the unlocking eccentric groove 943. Since the bottom plane of the unlocking eccentric groove 943 is further away from the axis of rotation, the hook part 922 can be further away from the engaging part of the limiting plate 91. At this time, when the movable handle 8 approaches the cylinder body 1, the hook part 922 of the locking hook 92 does not interfere with the engaging part of the limiting plate 91. Therefore, the locking hook 92 will not affect the movement of the movable handle 8.

[0078] In another embodiment, the eccentric structure can be an eccentric groove, with the other side being the sidewall of the switch locking pin 94, which also enables the locking hook 92 to switch between the locked and unlocked positions.

[0079] Preferably, the switch locking pin 94 is marked with a locking icon and an unlocking icon to indicate to the user the current status of the handle locking mechanism 9.

[0080] Preferably, such as Figure 13 As shown, the reset member 93 is a torsion spring and is fitted on the torsion spring mounting part 924 of the lock hook 92. The torsion spring mounting part 924 is coaxially arranged with the rotating part 921. One end of the torsion spring abuts against the hook part 922 and the other end abuts against the switch locking pin 94, which is used to drive the lock hook 92 to move closer to the limiting plate 91. At the same time, the position of the approach is restricted by the switch locking pin 94.

[0081] In another embodiment, the cylinder body 1 is made of a lightweight metal material and the limiting plate 91 is made of a high-strength material, thereby reducing the weight of the entire cylinder body and the hydraulic tool.

[0082] In this embodiment, the cylinder body 1 and the limiting plate 91 are set separately, which can reduce the strength requirements of the cylinder body 1. The cylinder body 1 can preferably be made of lightweight aluminum, while the limiting plate 91 can be made of stronger metal materials such as cast iron or other high-strength composite materials, thereby reducing the overall weight of the hydraulic tool and ensuring its service life. At the same time, if the limiting plate 91 fails, only the limiting plate 91 needs to be replaced, without replacing the cylinder body 1, which greatly reduces maintenance costs and maintenance difficulty.

[0083] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A hydraulic tool, characterized in that, include: The cylinder body (1) is provided with an inlet channel (11) and a pressure relief channel (12). The inlet channel (11) is provided with an inlet check valve (3), a plunger assembly (4) and an outlet check valve (5) in sequence. The clamp head mounting base (6) is installed at the front end of the cylinder (1) and forms a piston chamber (13) between the cylinder (1) and the cylinder (1). The piston chamber (13) is connected to the liquid outlet of the liquid inlet channel (11) and the liquid inlet of the pressure relief channel (12). An oil bag (14) is installed at the rear end of the cylinder (1) and connects the inlet end of the liquid inlet channel (11) and the outlet end of the pressure relief channel (12); and An automatic pressure relief valve (2) is installed at the liquid outlet end of the pressure relief channel (12) to realize automatic pressure relief of the piston chamber (13); The automatic pressure relief valve (2) includes: The pressure relief valve body (21) has a valve core mounting cavity; The pressure relief valve seat (22) has a valve seat connection portion (221) for connecting to the pressure relief valve body (21) and a valve seat fixing portion (222) for extending outward from the outside of the pressure relief valve body (21). The valve seat fixing portion (222) can be fixed on the pressure relief channel (12). The pressure relief valve seat (22) also has a valve seat channel (223) connecting the pressure relief channel (12) and the valve core mounting cavity. The pressure relief valve core assembly is installed in the valve core mounting cavity and is used to control the opening and closing of the valve seat channel (223); The pressure relief valve seat (22) can fix the pressure relief valve body (21) at the liquid outlet end of the pressure relief channel (12).

2. A hydraulic tool according to claim 1, characterized in that, The pressure relief valve body (21) has a valve seat mounting hole (211) at its mounting end, and a limiting step (212) is provided on the inner side of the valve seat mounting hole (211). The valve seat connection (221) has a limiting flange (2211) that is adapted to the limiting step (212).

3. A hydraulic tool according to claim 2, characterized in that, The valve seat fixing part (222) is an externally threaded part; The diameter of the valve seat connecting part (221) is larger than the diameter of the valve seat fixing part (222), and a sealing gasket (24) is fitted on the valve seat fixing part (222).

4. A hydraulic tool according to any one of claims 1-3, characterized in that, The pressure relief valve core assembly has: The pressure relief pin (25) has a pin seal (251) that blocks the valve seat passage (223). The pressure relief piston (28) is fitted onto the pressure relief pin (25); A pressure relief spring (26) is fitted onto the pressure relief pin (25); and The spring-loaded pressure regulating seat (27) is threadedly fixed to the pressure regulating end of the pressure relief valve body (21); The pressure relief spring (26) abuts against the pressure relief piston (28) and the spring adjusting seat (27), and is used to drive the pressure relief pin (25) to seal the valve seat passage (223) through the pressure relief piston (28). The pressure relief valve body (21) is provided with at least one first pressure relief hole (213) and a second pressure relief hole (214) that communicate with the valve core mounting cavity. The first pressure relief hole (213) can connect the space between the pressure relief piston (28) and the pressure relief valve seat (22); The second pressure relief hole (214) can connect the space between the pressure relief piston (28) and the spring pressure adjusting seat (27).

5. The hydraulic tool according to any one of claims 1-3, characterized in that, The outlet end of the pressure relief channel (12) is provided with an internal threaded hole for installation with the pressure relief valve seat (22) and a groove-shaped limiting part (121) for restricting the rotation of the pressure relief valve body (21). The pressure relief valve body (21) is provided with an irregular limiting wall (215) on the outer side of the mounting end, which is connected to the groove-shaped limiting part (121) to prevent the pressure relief valve body (21) from rotating.

6. The hydraulic tool according to claim 1, characterized in that, It also includes a manual pressure relief valve (7) disposed on the pressure relief passage (12), which comprises: Valve mounting base (73) has a pressure relief valve hole; The valve ball (72) seals the pressure relief valve orifice by means of the first spring (71); A valve push rod (74), disposed on the outside of the valve mounting seat (73) via a second spring (75), extends out of the cylinder body (1) at its outer end and its inner end can pass through the pressure relief valve hole to press the valve ball (72); and Press the handle (76), which is rotated on the cylinder (1). Pressing the handle (76) will drive the valve rod (74) and the valve ball (72) to move and open the pressure relief valve hole, thereby realizing manual pressure relief.

7. The hydraulic tool according to claim 1, characterized in that, A movable handle (8) for driving the piston assembly (4) to move is hinged to the cylinder (1), and a handle locking mechanism (9) is provided between the movable handle (8) and the cylinder (1). The handle locking mechanism (9) includes: A limiting plate (91) is fixed on the cylinder body (1); The locking hook (92) is movably mounted on the movable handle (8) and has a locked position and an unlocked position; Reset member (93) for driving the locking hook (92) closer to the limiting plate (91); and Switching pin (94) is used to control the locking hook (92) to be in the locked or unlocked position; When in the locked position, the locking hook (92) can engage with the limiting plate (91) to lock the movable handle (8). When in the unlocked position, the locking hook (92) and the limiting plate (91) do not interfere with each other on the path of the active handle (8).

8. The hydraulic tool according to claim 7, characterized in that, The locking hook (92) has: A rotating part (921) is rotatably mounted on the movable handle (8); A hook (922) is provided on one side of the rotating part (921) for engaging with the limiting plate (91); and The limiting part (923) abuts against the switch locking pin (94).

9. The hydraulic tool according to claim 8, characterized in that, The switch locking pin (94) is rotatably mounted on the movable handle (8), and a manual knob (941) is provided at the outer end. The switch locking pin (94) is provided with an eccentric structure in the middle for abutting the limiting part (923). The position of the locking hook (92) can be changed by rotating the eccentric structure. The eccentric structure includes: A locking eccentric groove (942) is provided on one side of the switch locking pin (94); Or / and, unlock the eccentric groove (943), located on the other side of the switch locking pin (94); When in the locked position, the limiting part (923) of the locking hook (92) abuts against the bottom plane of the locking eccentric groove (942); In the unlocked position, the limiting part (923) of the locking hook (92) abuts against the bottom plane of the unlocking eccentric groove (943).

10. The hydraulic tool according to any one of claims 7-9, characterized in that, The cylinder body (1) is made of lightweight metal material, and the limiting plate (91) is made of high-strength material.

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