Relief valve and hydraulic motor having the same

Abstract

The present invention relates to the technical field of hydraulic control valves, and in particular to a relief valve and a hydraulic motor having the same. A relief valve includes a valve body, a valve core and a pressure regulating spring. The valve body is provided with an inlet and an outlet for medium circulation. The pressure regulating spring is provided at one end of the valve core to drive the valve core to close the inlet. The valve core includes: a blocking portion, which is provided at the end of the valve core away from the pressure regulating spring. A conical surface is formed on the peripheral surface of the blocking portion, and the conical surface is suitable for abutting against the inlet to close the inlet; and a shoulder arranged at intervals from the blocking portion; wherein the taper of the conical surface is θ, and the value range of θ is [59.5, 60.5] degrees; and in the axial direction of the valve core, there is a shortest spacing L between the shoulder and the blocking portion, and the value range of L is [1.3, 1.4] mm. Through fluid simulation experiments, it is found that the combined force of the hydraulic force and the jet force of the valve core structure within the above numerical range is small, and the hindrance to the opening and closing of the valve core is small, which can ensure that the valve core opens and closes more quickly.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control valves, and in particular to a relief valve and a hydraulic motor having the same. Background Art

[0002] When power equipment such as excavators are started and braked, the load on the traveling mechanism will increase instantaneously, resulting in large impact inside the traveling mechanism. Related parts will be severely worn when impacted, shortening their service life.

[0003] In order to reduce the negative impact of the hydraulic shock caused by the instantaneous increase in load, a buffer relief valve is usually installed at an appropriate position in the hydraulic system, such as the end cover of the hydraulic motor. When a buffer relief valve is used, a return spring is provided at the rear end of the valve core, and the return spring abuts the valve core against the oil inlet to close the oil port. When the load increases, the high-pressure liquid impacts the front end of the relief valve core, the valve core retreats, the oil discharge port opens, and the pressure is released, thereby solving the problem of hydraulic shock.

[0004] However, when high-pressure liquid acts on the front end of the valve core, the valve core is subjected to the pressure of the high-pressure liquid and the supporting force of the return spring. Because the high-pressure liquid is flowing, it is also subjected to the impact force of the liquid. Poor control of the liquid impact force can easily lead to uneven force on the valve core, large overflow pressure difference, and long opening and closing time of the overflow valve, which seriously affects the starting and braking performance of the construction machinery excavator when traveling and rotating, and may cause phenomena such as "slippage" and "insufficient starting force" when the excavator rotates or travels. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the long opening and closing time of the overflow valve affects the operating performance of the power equipment, thereby providing a overflow valve and a hydraulic motor having the same.

[0006] In order to solve the above problems, the present invention provides a relief valve, including a valve body, a valve core and a pressure regulating spring, wherein the valve body is provided with an inlet and an outlet for medium circulation, the pressure regulating spring is provided at one end of the valve core to drive the valve core to close the inlet, and the valve core comprises: a blocking portion, which is provided at one end of the valve core away from the pressure regulating spring, and a conical surface is formed on the circumferential surface of the blocking portion, and the conical surface is suitable for abutting against the inlet to close the inlet;

[0007] And a shoulder arranged at intervals from the blocking portion; wherein the taper of the conical surface is θ, and the value range of θ is [59.5, 60.5] degrees; and in the axial direction of the valve core, there is a shortest distance L between the shoulder and the blocking portion, and the value range of L is [1.3, 1.4] mm.

[0008] Optionally, the value of θ is 60°, and the value of L is 1.3 mm.

[0009] Optionally, the valve body is a cylindrical structure with openings at both ends, and an annular stopper is provided on the inner circumference of the valve body;

[0010] A sliding cavity is formed in the middle of the annular stopper, and a sliding rod cooperating with the sliding cavity is formed on the valve core;

[0011] And an overflow chamber and a spring chamber are respectively arranged at two ends of the sliding chamber, the overflow chamber contains the blocking portion and the stop shoulder, and the spring chamber contains the pressure regulating spring.

[0012] Optionally, the opening of the valve body close to the overflow chamber is configured as the inlet, and the outlet is formed on the peripheral wall of the overflow chamber;

[0013] Wherein, the peripheral surface of the shoulder partially blocks the outlet.

[0014] Optionally, it further comprises a first valve seat, which is a cylindrical structure with openings at both ends and is detachably arranged on the inlet;

[0015] Wherein, the maximum diameter dimension of the radial cross section of the valve core is not greater than the diameter dimension of the inlet.

[0016] Optionally, a flange is formed at one end of the first valve seat, the flange is embedded in the inlet, and the conical surface is suitable for abutting against the outer edge of the flange.

[0017] Optionally, a second valve seat is further included, which is arranged at an opening at one end of the valve body, and the second valve seat includes:

[0018] A body, which is detachably arranged on the valve body and has an adjusting chamber arranged inside;

[0019] A first spring seat, slidably disposed in the regulating cavity, one end of which is suitable for supporting the pressure regulating spring;

[0020] A pressure regulating member is movably arranged on the main body, and one end of the first spring seat which is away from the pressure regulating spring is abutted by the pressure regulating member.

[0021] Optionally, a throttle port is provided in the axial direction of the valve core, the throttle port is connected to the spring chamber, a buffer piston is slidably provided on the outer peripheral wall of the spring chamber, and a buffer port is provided on the spring chamber.

[0022] The present invention also provides a hydraulic motor, comprising: a base; and an overflow valve as described in any one of the above described arrangements on the base, wherein the inlet of the overflow valve is connected to the oil inlet chamber of the hydraulic motor, and the outlet is connected to the oil outlet chamber of the hydraulic motor.

[0023] Optionally, at least two of the overflow valves are arranged on the oil inlet chamber and the oil outlet chamber, and a buffer chamber is also arranged on the base, the buffer chamber is respectively connected to the oil inlet chamber and the oil outlet chamber, and the outlets of the two overflow valves are both connected to the buffer chamber.

[0024] The technical solution of the present invention has the following advantages:

[0025] 1. The overflow valve in the present invention includes a valve body, a valve core and a pressure-regulating spring. The valve body is provided with an inlet and an outlet for medium circulation. The pressure-regulating spring is arranged at one end of the valve core to drive the valve core to close the inlet. The valve core includes: a blocking portion, which is arranged at the end of the valve core away from the pressure-regulating spring. A conical surface is formed on the circumferential surface of the blocking portion, and the conical surface is suitable for abutting against the inlet to close the inlet; and a shoulder arranged at intervals from the blocking portion; wherein the taper of the conical surface is θ, and the value range of θ is [59.5, 60.5] degrees; and in the axial direction of the valve core, there is a shortest spacing L between the shoulder and the blocking portion, and the value range of L is [1.3, 1.4] mm.

[0026] As described in the background technology section of the present invention, those skilled in the art have found that the force conditions at the valve core include the pressure of the medium fluid on the valve core and the jet force in the positive direction, and the pressure of the pressure regulating spring on the valve core and the hydraulic force in the reverse direction. On the basis of the above force distribution, in order to ensure the rapid opening and closing of the valve core, it is necessary to use the jet force to compensate for the hydraulic force generated when the valve core is working. On this basis, the inventor has made improvements to the structural dimensions of the valve core, specifically, the taper of the cone surface is θ, and the value range of θ is [59.5, 60.5] degrees; and in the axial direction of the valve core, there is a shortest distance L between the shoulder and the blocking part, and the value range of L is [1.3, 1.4] mm. Within the above range, through fluid simulation experiments, it is found that the combined force of the hydraulic force and the jet force is small, and the hindrance to the opening and closing of the valve core is small, which can ensure that the valve core opens and closes more quickly.

[0027] 2. In the overflow valve of the present invention, θ is taken as 60°, and L is taken as 1.3 mm. According to the data curve of the simulation experiment, when the above values ​​are met, the combined force of the hydraulic force and the jet force is the smallest, and the resistance to the opening and closing of the valve core is the smallest.

[0028] 3. In the overflow valve of the present invention, the opening of the valve body close to the overflow cavity is constructed as an inlet, and the outlet is formed on the peripheral wall of the overflow cavity; wherein the peripheral surface of the shoulder blocks the outlet. When the valve core blocks the inlet, the shoulder will also block the outlet accordingly to ensure that the hydraulic equipment works under normal pressure and prevents leakage of the overflow valve. When the oil pressure at the inlet increases, the valve core retreats, and because the shoulder can only block part of the outlet, the outlet will be opened to achieve normal overflow function.

[0029] 4. The overflow valve in the present invention also includes a first valve seat, which is a cylindrical structure with openings at both ends, and is detachably arranged on the inlet; wherein the maximum diameter dimension at the radial cross section of the valve core is not greater than the diameter dimension of the inlet. This size relationship can ensure that when the valve core is installed, the valve core can be directly placed into the valve body from the inlet, and then the first valve seat is installed to fix the valve core, which is convenient for the installation of the valve core and the subsequent maintenance and replacement.

[0030] 5. A throttle port is provided in the axial direction of the valve core of the overflow valve of the present invention, and the throttle port is connected to the spring chamber. A buffer piston is slidably provided on the outer peripheral wall of the spring chamber, and a buffer port is provided on the spring chamber. When the oil pressure at the oil inlet increases but has not yet reached the triggering pressure for opening the valve core of the overflow valve, the high-pressure oil flows through the throttle port and acts on the buffer piston via the buffer port, pushing the buffer piston to move to release the pressure.

[0031] 6. In the hydraulic motor of the present invention, at least two overflow valves are arranged on the oil inlet chamber and the oil outlet chamber, and a buffer chamber is also arranged on the base body, which is connected to the oil inlet chamber and the oil outlet chamber respectively, and the outlets of the two overflow valves are connected to the buffer chamber. In the hydraulic motor, the oil inlet chamber and the oil outlet chamber can generally be switched between the two according to the working state of use. In order to ensure that the pressure in the oil chamber is unloaded when the oil inlet chamber and the oil outlet chamber are switchable, overflow valves are arranged on the oil inlet chamber and the oil outlet chamber respectively, and the outlets of the two overflow valves are connected to the buffer chamber, so as to reduce the complexity of the internal oil circuit of the hydraulic motor and ensure the compactness of its structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A cross-sectional view of the relief valve in Example 1 provided by the present invention;

[0034] Figure 2 A cross-sectional view of the valve core in Embodiment 1 provided by the present invention;

[0035] Figure 3 A partial enlarged view of the overflow valve in Example 1 provided by the present invention;

[0036] Figure 4 A cross-sectional view of a hydraulic motor in Embodiment 2 provided by the present invention;

[0037] Figure 5A schematic diagram of a fluid simulation result of the relief valve in Example 1 provided by the present invention;

[0038] Figure 6 A partial enlarged view of the fluid simulation result of the relief valve in Example 1 provided by the present invention;

[0039] Figure 7 A curve diagram showing the change of the liquid combined force with the shoulder width in Example 1 provided by the present invention;

[0040] Figure 8 This is a curve diagram showing the change of the liquid combined force with the valve core cone angle in Example 1 provided by the present invention.

[0041] Description of reference numerals:

[0042] 1-valve body; 11-inlet; 12-outlet; 13-annular stopper; 14-overflow chamber; 15-spring chamber; 151-buffer port;

[0043] 2-valve core; 21-blocking part; 22-shoulder; 23-sliding rod; 24-throttle port; 211-conical surface;

[0044] 3-pressure regulating spring;

[0045] 4-first valve seat; 41-flange;

[0046] 5 - second valve seat; 51 - body; 52 - regulating chamber; 53 - first spring seat; 54 - pressure regulating member;

[0047] 6 - Buffer piston;

[0048] 7-base; 71-oil inlet chamber; 72-oil outlet chamber; 73-buffer chamber;

[0049] 8 - Second spring seat. DETAILED DESCRIPTION

[0050] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0054] Example 1

[0055] like Figures 1 to 3 , Figures 5 to 8 As shown, a relief valve provided in the present embodiment includes a valve body 1, a valve core 2 and a pressure regulating spring 3. The valve body 1 is provided with an inlet 11 and an outlet 12 for medium circulation. The pressure regulating spring 3 is arranged at one end of the valve core 2 to drive the valve core 2 to close the inlet 11. The valve core 2 includes: a blocking portion 21, which is arranged at the end of the valve core 2 away from the pressure regulating spring 3. A conical surface 211 is formed on the circumferential surface of the blocking portion 21, and the conical surface 211 is suitable for abutting against the inlet 11 to close the inlet 11; and a shoulder 22 arranged at a distance from the blocking portion 21; wherein the taper of the conical surface 211 is θ, and the value range of θ is [59.5, 60.5] degrees; and in the axial direction of the valve core 2, there is a shortest spacing L between the shoulder 22 and the blocking portion 21, and the value range of L is [1.3, 1.4] mm.

[0056] The overflow valve in this embodiment is used as a safety valve for the hydraulic motor that controls the rotation and travel of the excavator, and the medium flowing inside it is hydraulic oil. As a variation, the overflow valve in this embodiment can also be used on power equipment in common engineering machinery, such as transmissions, oil cylinders, etc. As a variation, the medium flowing in the overflow valve in this embodiment can also be gas or small-diameter solid particles.

[0057] The inlet 11 in this embodiment is responsible for connecting the oil inlet end of the device to be depressurized to reduce the oil pressure at the oil inlet end. It should also be noted that a relevant chamber is provided in the valve body 1 in this embodiment (which will be described in detail later), and the valve core performs a piston-like movement in the chamber to realize the opening and closing of the inlet 11. When the inlet 11 is opened, the high-pressure oil flows in through the inlet 11 and flows out from the outlet 12 to realize the pressure relief function.

[0058] Furthermore, the pressure-regulating spring 3 in this embodiment is a common compression spring. As a commonly used implementation, one end of the pressure-regulating spring abuts against the valve body 1, and the other end abuts against the valve core 2. The valve core 2 relies on the sum of the elastic force of the spring and the liquid pressure in the spring chamber to achieve blocking of the inlet 11.

[0059] The relief valve in this embodiment has the following effects: As described in the background technology section, those skilled in the art find that the force on the valve core includes the pressure of the medium fluid on the valve core and the jet force in the positive direction, and the pressure of the pressure regulating spring on the valve core and the hydraulic force in the reverse direction. The force relationship is:

[0060] Formula 1: ;

[0061] Formula 2: ;

[0062] Formula 3: ;

[0063] Formula 4: ;

[0064] Formula 5: D1>D2;

[0065] D1: The radial cross-sectional diameter of the pressure-bearing surface of the valve core sealing part; D2: The diameter of the valve core sliding rod;

[0066] The opening of the relief valve depends on the area difference on both sides of the valve core. 进口压力 When the relief pressure setting value is reached, F 压 > Spring force pushes the valve core to open and protect the system. Formula 1 is the force balance process of the valve core during opening.

[0067] On the basis of the above force distribution, in order to ensure the rapid opening of the valve core, it is necessary to use the jet force to compensate for the hydraulic force generated when the valve core is working. On this basis, the inventors have made improvements to the structural dimensions of the valve core. Specifically, the taper of the cone is θ, and the value range of θ is [59, 61] degrees; and in the axial direction of the valve core, there is a shortest distance L between the shoulder and the blocking part, and the value range of L is [1.3, 1.5] mm. Within the above range, fluid simulation experiments have found that the combined force of the hydraulic force and the jet force is small, and the hindrance to the opening and closing of the valve core is small, which can ensure that the valve core opens and closes faster.

[0068] The specific simulation results are as follows:

[0069] See also Figure 7 B in the figure shows the change of the fluid force, and C shows the change of the jet force. The following can be obtained from the above:

[0070] Parameter optimization of shoulder size L:

[0071] In the following table: The total force on the valve core refers to: F 压1 , F jet force, F fluid force; static pressure refers to: F 压2 and F 弹

[0072]

[0073] Table 1

[0074] From Table 1 and Table 7, it can be obtained that the liquid combined force refers to the combined force of the liquid force and the jet force. When the θ value is fixed (taken as 60°), as L increases, the pressure at the valve core shoulder decreases, and the liquid force and the jet force on the valve core gradually increase ("+" is the opening direction of the valve core). Therefore, when L is greater than or equal to 1.3mm and less than or equal to 1.4mm, the value of the liquid combined force is small, which is conducive to the opening and closing of the valve core.

[0075] Parameter optimization of valve core cone angle α:

[0076]

[0077] Table 2

[0078] See Table 2 and Figure 8 As shown, the L value is fixed. As θ increases, the pressure at the valve core shoulder increases, and the liquid force and jet force acting on the valve core gradually increase ("+" is the valve core opening direction). When θ is greater than or equal to 59.5 degrees and less than or equal to 60.5 degrees, the value of the liquid force is the smallest, which is conducive to the opening and closing of the valve core.

[0079] Based on the above embodiment, as a further limitation, θ is 60° and L is 1.3 mm. From the above simulation and experimental test tables, it can be directly concluded that when the above values ​​are taken, the value of the liquid combined force is the smallest, and the effect on the opening and closing of the valve core is the smallest.

[0080] On the basis of the above embodiment, as a further limitation, as a specific implementation method of this embodiment, as follows Figure 1As shown in the figure, the valve body 1 is a cylindrical structure with openings at both ends, and an annular stopper 13 is provided on the inner peripheral surface in the middle. The annular stopper 13 is directly integrally formed on the valve body 1, and a sliding cavity is formed in the middle annular hollow part. A sliding rod 23 cooperating with the sliding cavity is formed on the valve core 2, and a clearance is adopted between the sliding rod 23 and the sliding cavity. Furthermore, in order to ensure the sealing performance of the cooperating part between the sliding rod and the sliding cavity, a plurality of sealing grooves are provided on the outer peripheral surface of the sliding rod 23 in this embodiment, and O-ring seals are embedded in the sealing grooves.

[0081] Furthermore, in this embodiment, an overflow chamber 14 and a spring chamber 15 are respectively provided at both ends of the sliding chamber, and the overflow chamber 14 is provided with a sealing portion 21 and a shoulder 22, and the spring chamber 15 is provided with a pressure-regulating spring 3. When the oil pressure at the inlet 11 changes, the valve core is pressed backward, and the sliding rod 23 of the valve core slides in the sliding chamber, while compressing the pressure-regulating spring 3 in the spring chamber, thereby realizing the opening of the inlet 11 and ensuring effective pressure relief.

[0082] On the basis of the above embodiment, as a further limitation, the opening of the valve body 1 close to the overflow chamber 14 is constructed as an inlet 11, and the outlet 12 is formed on the peripheral wall of the overflow chamber 14; wherein the peripheral surface of the shoulder 22 partially blocks the outlet 12. When the valve core 2 blocks the inlet 11, the shoulder 22 will also block the outlet 12 accordingly to ensure that the hydraulic equipment works under normal pressure and prevents leakage of the overflow valve. When the oil pressure at the inlet 11 increases, the valve core retreats, and because the shoulder 22 can only block part of the outlet 12, the outlet 12 will be opened to achieve a normal overflow function.

[0083] As a variation, the inlet 11 can also be processed on the peripheral wall of the overflow chamber 14, which can also realize the overflow function. The position of the inlet 11 can be adaptively adjusted according to the connection arrangement with the pressure relief device.

[0084] On the basis of the above embodiment, as a further limitation, it also includes a first valve seat 4, which is a cylindrical structure with openings at both ends, and is detachably arranged on the inlet 11; wherein, the maximum diameter dimension at the radial cross section of the valve core 2 is not greater than the diameter dimension of the inlet 11. This size relationship can ensure that when the valve core is installed, the valve core can be directly placed into the valve body from the inlet, and then the first valve seat is installed to fix the valve core, which is convenient for the installation of the valve core and the subsequent maintenance and replacement. Furthermore, a flange 41 is formed at one end of the first valve seat 4, and the flange 41 is embedded in the inlet 11, and the conical surface 211 is suitable for abutting against the outer edge of the flange 41. Furthermore, in order to ensure the sealing of the oil port connection between the first valve seat 4 and the external device, an O-ring is also installed on the peripheral wall of the first valve seat.

[0085] On the basis of the above embodiment, as a further limitation, it also includes a second valve seat 5, which is arranged at the opening of one end of the valve body 1. The second valve seat 5 includes: a body 51, which is flange-shaped and detachably arranged on the valve body 1, specifically a crimping connection between a screw connection or an interference fit. The body 51 is provided with an adjusting chamber 52 inside, and the adjusting chamber is connected with the spring chamber. It also includes a first spring seat 53, which is slidably arranged in the adjusting chamber 52, and a protrusion is provided at one end. The pressure regulating spring is sleeved in the above protrusion to ensure the stability of the fixation. It also includes a pressure regulating member 54, which is movably arranged on the body 51. The end of the first spring seat 53 away from the pressure regulating spring 3 is abutted by the pressure regulating member 54. Specifically, the pressure regulating member 54 in this embodiment is a common bolt. The body 51 is provided with a screw hole for installing the bolt. When the bolt is screwed, it abuts against one end of the first spring seat 53, pushing the first spring seat 53 to move toward the spring chamber. The pressure regulating process is as follows:

[0086] The oil pressure at the inlet 11 comes over, compressing the valve core to retreat. At this time, the compression amount of the pressure-adjusting spring is adjusted by screwing the bolt, driving the valve core to move forward and block the inlet 11. The pressure gauge set on the second valve seat is used to observe whether the spring pressure on the valve core reaches the preset value. If so, the position of the bolt can be locked with a nut.

[0087] Furthermore, in this embodiment, a second spring seat 8 is detachably mounted on one end of the valve core away from the blocking portion, and the detachable mounting facilitates the direct installation of the valve core 2 from the inlet 11, and the second spring seat 8 is then installed from the opening of the second valve seat. As a variation, the second spring seat 8 can also be directly integrally formed on the valve core 2 to simplify the assembly steps. In this case, the size of the second spring seat 8 should be controlled to ensure the installation of the valve core.

[0088] On the basis of the above embodiment, as a further limitation, a throttle port 24 is provided in the axial direction of the valve core 2, the throttle port 24 is connected to the spring chamber 15, a buffer piston 6 is slidably provided on the outer peripheral wall of the spring chamber 15, and a buffer port 151 is provided on the spring chamber 15. When the oil pressure at the inlet increases, but has not yet reached the triggering pressure for the valve core of the relief valve to open, the high-pressure oil flows through the throttle port and acts on the buffer piston through the buffer port, pushing the buffer piston to move to release the pressure, thereby realizing the multi-stage adjustment function of the pressure oil.

[0089] Example 2

[0090] like Figure 4 As shown, a hydraulic motor provided in this embodiment includes: a base 7, which is an end cover of the hydraulic motor in this embodiment, and an overflow valve A arranged on the base 7, wherein the inlet 11 of the overflow valve A is connected to the oil inlet chamber 71 of the hydraulic motor, and the outlet is connected to the oil outlet chamber 72 of the hydraulic motor.

[0091] In this embodiment, two relief valves are arranged on the oil inlet chamber 71 and the oil outlet chamber 72, and a buffer chamber 73 is also arranged on the base 7. The buffer chamber 73 is communicated with the oil inlet chamber 71 and the oil outlet chamber 72 respectively, and the outlets 12 of the two relief valves are communicated with the buffer chamber 73. In a hydraulic motor, the oil inlet chamber and the oil outlet chamber are generally switchable according to the working state. In order to ensure that the pressure in the oil chamber is unloaded when the oil inlet chamber and the oil outlet chamber are switchable, relief valves are arranged on the oil inlet chamber and the oil outlet chamber respectively, and the outlets of the two relief valves are connected to the buffer chamber, so as to reduce the complexity of the internal oil circuit of the hydraulic motor and ensure the compactness of its structure.

[0092] Furthermore, in order to realize the installation of the relief valve A, a mounting groove is processed on the base 7. In order to ensure the sealing of the relief valve installed on the base 7, a sealing ring is further installed on the peripheral surface of the second valve seat.

[0093] Furthermore, in order to ensure the normal movement of the buffer piston 6, a corresponding avoidance groove is processed in the above-mentioned installation groove to ensure the movement stroke of the buffer piston and ensure effective pressure relief.

[0094] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A relief valve, comprising a valve body (1), a valve core (2) and a pressure regulating spring (3), wherein the valve body (1) is provided with an inlet (11) and an outlet (12) for medium flow, and the pressure regulating spring (3) is arranged at one end of the valve core (2) to drive the valve core (2) to close the inlet (11), characterized in that: The valve core (2) comprises: A blocking portion (21) is arranged at an end of the valve core (2) away from the pressure regulating spring (3), a conical surface (211) being formed on a peripheral surface of the blocking portion (21), the conical surface (211) being suitable for abutting against the inlet (11) to close the inlet (11); and a stop shoulder (22) arranged at a distance from the blocking portion (21); in, The taper of the conical surface (211) is θ, and the value range of θ is [59.5, 60.5] degrees; In the axial direction of the valve core (2), there is a shortest distance L between the stop shoulder (22) and the blocking portion (21), and the value range of L is [1.3, 1.4] mm; The valve body (1) is a cylindrical structure with openings at both ends, and an annular stopper (13) is provided on the inner peripheral surface thereof; A sliding cavity is formed in the middle of the annular stopper (13), and a sliding rod (23) cooperating with the sliding cavity is formed on the valve core (2); and an overflow chamber (14) and a spring chamber (15) respectively arranged at two ends of the sliding chamber, the overflow chamber (14) containing the blocking portion (21) and the stop shoulder (22), and the spring chamber (15) containing the pressure regulating spring (3); The opening of the valve body (1) close to the overflow chamber (14) is configured as the inlet (11), and the outlet (12) is formed on the peripheral wall of the overflow chamber (14); Wherein, the peripheral surface of the shoulder (22) partially blocks the outlet (12); It also comprises a first valve seat (4) which is a cylindrical structure with openings at both ends and is detachably arranged on the inlet (11); Wherein, the maximum diameter dimension of the radial cross section of the valve core (2) is not greater than the diameter dimension of the inlet (11); A flange (41) is formed at one end of the first valve seat (4), the flange (41) is embedded in the inlet (11), and the conical surface (211) is suitable for abutting against the outer edge of the flange (41).

2. The relief valve according to claim 1, characterized in that: The value of θ is 60°, and the value of L is 1.3 mm.

3. The relief valve according to claim 1, characterized in that: It also includes a second valve seat (5) arranged at an opening at one end of the valve body (1), and the second valve seat (5) includes: A body (51) is detachably arranged on the valve body (1), and an adjusting chamber (52) is arranged inside the body; A first spring seat (53) is slidably disposed in the regulating cavity (52), one end of which is suitable for supporting the pressure regulating spring (3); A pressure regulating member (54) is movably arranged on the main body (51), and one end of the first spring seat (53) facing away from the pressure regulating spring (3) is abutted by the pressure regulating member (54).

4. The relief valve according to claim 1, characterized in that: A throttle port (24) is provided in the axial direction of the valve core (2), the throttle port (24) is connected to the spring chamber (15), a buffer piston (6) is slidably provided on the outer peripheral wall of the spring chamber (15), and a buffer port (151) is provided on the spring chamber (15).

5. A hydraulic motor, characterized in that: include: Matrix (7); And an overflow valve according to any one of claims 1 to 4 is arranged on the base (7), the inlet (11) of the overflow valve is connected to the oil inlet chamber (71) of the hydraulic motor, and the outlet (12) is connected to the oil outlet chamber (72) of the hydraulic motor.

6. The hydraulic motor according to claim 5, characterized in that: At least two overflow valves are arranged on the oil inlet chamber (71) and the oil outlet chamber (72), and a buffer chamber (73) is also arranged on the base body (7), the buffer chamber (73) is communicated with the oil inlet chamber (71) and the oil outlet chamber (72) respectively, and the outlets (12) of the two overflow valves are both communicated with the buffer chamber (73).

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