CN114087248B

CN114087248B - Reversing valve

Info

Publication number: CN114087248B
Application number: CN202111287036.9A
Authority: CN
Inventors: 何贤剑; 钟麒; 陈净生; 高振家; 王军; 张辉; 秦宇; 杜黄方
Original assignee: Zhejiang Haihong Hydraulic Technology Co ltd
Current assignee: Zhejiang Haihong Hydraulic Technology Co ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2022-07-26
Anticipated expiration: 2041-11-02
Also published as: CN114087248A; WO2023077630A1

Abstract

The invention provides a reversing valve, and belongs to the technical field of hydraulic pressure. The hydraulic lock solves the problems that the sinking amount of the existing oil cylinder in a pressure maintaining state is large, and the hydraulic lock is unlocked inconveniently. This switching-over valve includes the hydraulic pressure lock, the valve rod and the valve body that has work oil inlet and main oil circuit, the valve rod has the face of unblock and the activity is worn to locate in the main oil circuit, the hydraulic pressure lock includes the spring and links firmly the lock seat in the valve body, the hydraulic pressure lock is still including being rectangular form and being located the lock core between work oil inlet and the main oil circuit, the one end of lock core can be supported and to lean on the face of unblock, enclose between the other end of lock core and the lock seat and close and form the spring chamber, the spring is located the spring chamber and tip elasticity supports and lean on lock seat and lock core, set up the pressure release hole that communicates spring chamber and main oil circuit on the lock core. The reversing valve has the advantages of improving the pressure maintaining effect of the oil cylinder and reducing the settling volume of the oil cylinder in a pressure maintaining state.

Description

Reversing valve

Technical Field

The invention belongs to the technical field of hydraulic pressure, and relates to a reversing valve.

Background

The reversing valve comprises a valve rod and a valve body with a main oil way, a working oil inlet and a working oil outlet, wherein the valve rod penetrates through the main oil way and can move to a lifting position, a middle position, a descending position and a floating position at a specific position relative to the valve body so as to realize communication, cutting off and reversing of the hydraulic oil way. When the valve rod can jump to the middle position from the rising position, the oil cylinder output by the working oil inlet enters a pressure maintaining state, oil liquid backflow needs to be avoided as far as possible under the pressure maintaining state, and namely the oil liquid flows to the main oil way through the working oil inlet. The existing reversing valve reduces the oil return flow by reducing the fit clearance between the valve rod and the main oil way, so as to maintain the pressure maintaining state of the lifting oil cylinder. However, along with the superposition of the moving times of the valve rod relative to the valve body, the fit clearance can be gradually increased, so that the pressure maintaining performance of the lifting oil cylinder is continuously reduced along with the use of the reversing valve, and further the sedimentation amount of the lifting oil cylinder is large; and with the increase of horsepower of the existing agricultural machinery, particularly tractors, objects needing to be lifted by the lifting oil cylinder are heavier, which also puts higher requirements on the settling volume of the lifting oil cylinder in a pressure maintaining state.

In order to solve the problem of large sinking and dropping amount of the reversing valve in a pressure maintaining state, a hydraulic lock is additionally arranged between a working oil inlet and a main oil way. For example, chinese patent literature discloses a mechanical leakage-free multi-way valve [ application number: 201711034467.8; application publication No.: CN107620810A ], including valve body and valve rod, the valve body on be equipped with oil inlet, oil-out, first working port, second working port and cavity, the valve body in be equipped with the check valve that has the hydraulic lock function, the check valve locate between cavity and the second working port, the valve rod have make oil inlet pressure oil through cavity, check valve and second working port be linked together make first working port and oil-out be linked together simultaneously the first position, make oil inlet and oil-out be linked together and the pressure oil of second working port pass through the second position of check valve locking, open the third position that the check valve made second working port and oil-out be linked together.

When the valve rod rebounds to the middle position from the rising position, the pressure of the lifting oil cylinder needs to be relieved, the valve rod moves to the right at the moment, the second valve core is jacked up by the valve rod, the pressure of the cavity and the pressure of the second working port are balanced, the opening resistance of the first valve core is reduced, and the valve rod can conveniently push the first valve core through the push rod. That is to say, before pushing the check valve, because the oil pressure that promotes the hydro-cylinder is greater than the oil pressure of cavity and leads to first case to move the resistance big, so before promoting first case and remove, need push first second case earlier and balance pressure, push first case again, this structure leads to the hydraulic lock to have the inconvenient problem of unblock.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a reversing valve which solves the technical problems that the sinking and dropping amount of an oil cylinder in a pressure maintaining state is large, and meanwhile, a hydraulic lock is inconvenient to unlock.

The purpose of the invention can be realized by the following technical scheme: a reversing valve comprises a hydraulic lock, a valve rod and a valve body with a working oil inlet and a main oil way, wherein the valve rod is provided with an unlocking surface and movably penetrates through the main oil way, the hydraulic lock comprises a spring and a lock seat fixedly connected in the valve body, it is characterized in that the hydraulic lock also comprises a lock core which is in a strip shape and is positioned between the working oil inlet and the main oil way, one end of the lock core can be abutted against the unlocking surface, a spring cavity is enclosed between the other end of the lock core and the lock seat, the spring is positioned in the spring cavity, the end part of the spring is elastically abutted against the lock seat and the lock cylinder, the lock cylinder is provided with a pressure relief hole for communicating the spring cavity with the main oil way, when the valve rod is in the middle position, the lock core separates the working oil inlet and the main oil way under the elastic force of the spring, when the valve rod moves to enable the lock cylinder to overcome the elastic force of the spring to abut against the unlocking surface and enable the pressure relief hole to relieve pressure, the working oil inlet is communicated with the main oil way.

The valve rod can move to a specific position according to actual needs, and the specific position of the valve rod generally comprises a rising position, a middle position, a descending position and a floating position. When the valve rod is in the ascending position, oil in the main oil way supplies oil to the oil cylinder through the working oil inlet, when the valve rod returns to the middle position from the ascending position, the main oil way stops supplying oil to the oil cylinder, so that the oil cylinder is in a pressure maintaining state, and at the moment, the oil in the oil cylinder needs to be prevented from flowing back to the main oil way through the working oil inlet as far as possible. When the valve rod is positioned at the middle position, the valve core is enabled to separate the working oil port from the main oil path through the elastic action of the spring at one end of the valve core, the spring is positioned in a spring cavity formed by enclosing the lock core and the lock seat, the spring cavity is enabled to be in a closed state, namely, the oil pressure of the working oil inlet can not act on the lock core and the spring, the oil is required to flow from the working oil inlet to the main oil path, the valve core can only overcome the elasticity of the spring to move towards the lock seat by pushing one end of the valve core close to the valve rod, namely, the valve core can only be pushed by the unlocking surface by moving the position of the valve rod, the communication between the working oil inlet and the main oil path is realized, the structure furthest avoids the oil backflow when the valve rod returns to the middle position from the rising position, the pressure maintaining effect of the oil cylinder is improved, and the sedimentation amount of the oil cylinder in the pressure maintaining state is reduced. This application can use in tractor hydraulic system, and aforementioned hydro-cylinder is the hydro-cylinder of tractor.

Further, when the lock cylinder separates a working oil inlet and a main oil way, the spring cavity is not communicated with the working oil inlet, but is communicated with the main oil way through the pressure relief hole, when the valve rod pushes the lock cylinder through the unlocking surface, the pressure relief hole synchronously relieves pressure to reduce the influence of the oil pressure of the working oil inlet on the movement of the lock cylinder, and the lock cylinder is linked with the valve rod, namely, the valve rod directly drives the lock cylinder to move through the unlocking surface to communicate the working oil inlet and the main oil way, the pressure relief unlocking mode of the pressure relief lock is changed by the structure of the lock cylinder, a pilot structure is omitted for realizing the pressure relief, the unlocking mode that the lock cylinder is driven to move after the pressure relief in the prior art is avoided, the hydraulic lock structure is simplified, the processing difficulty is reduced, the sinking amount of the oil cylinder in a pressure maintaining state is reduced, and the unlocking convenience of the hydraulic lock is improved.

In the reversing valve, the lock seat is provided with a mounting hole, the lock cylinder is embedded into the mounting hole to form the spring cavity, and a sealing assembly which is used for radially positioning the lock cylinder and sealing the spring cavity is arranged between the lock cylinder and the mounting hole. The mounting hole makes the position of lock core confirm, forms the spring chamber with lock core embedding mounting hole for the one end of lock core is located the mounting hole, seal assembly not only seals the spring chamber, still avoids the position of lock core to take place the possibility of incline at the removal in-process as far as possible, when the hydro-cylinder is in the pressurize state, on the one hand spring and lock core all do not receive the influence of work oil inlet oil pressure force, on the other hand, under the prerequisite that the valve rod does not take place to remove, the lock core can not take place to remove, with the settlement volume under the reduction hydro-cylinder pressurize state.

In the above reversing valve, the valve body has an oil inlet path communicating the working oil inlet and the main oil path, the oil inlet path has a flow guide section and a transition section, the flow guide section is communicated with the main oil path through the transition section, the lock cylinder has a flow blocking portion located on the flow guide section, one side of the flow blocking portion is embedded in the mounting hole, and the other side of the flow blocking portion can block the transition section. Through locating the lock core on the oil feed way, the existing oil circuit in the valve body has rationally been utilized for the flow path of fluid does not change in the valve body, avoids additionally setting up the oil circuit that holds the hydraulic pressure lock on the valve body, and by this oil circuit intercommunication main oil circuit and oil feed way.

In the reversing valve, the flow blocking part is provided with the pressure relief hole, the pressure relief hole is communicated with the spring cavity and the transition section, and the diameter of the transition section is the same as the aperture of the mounting hole. Because of the diameter of changeover portion is the same with the aperture of mounting hole, and benefits from the position of pressure release hole for the pressure of the pressure in the spring chamber and the pressure of changeover portion can be balanced with the help of the pressure release hole, and then make the removal of lock core not influenced by oil pressure power, reduce the removal resistance of lock core, so the elastic force that the valve rod only need overcome the spring can directly drive the lock core and remove, improves the unblock convenience of hydraulic pressure lock from this.

In foretell switching-over valve, the accommodation hole has been seted up to one side of choked flow portion embedding mounting hole, the one end of spring supports and leans on the hole bottom of accommodation hole, and the other end supports and leans on the hole bottom of mounting hole, the lock core still has the ejector pin of wearing to locate in the changeover portion, choked flow portion is connected to the one end of ejector pin, and the other end of ejector pin can support and lean on the unblock face. The position that the accommodation hole made the spring act on the choked flow portion is definite, because the choked flow portion is connected to the one end of ejector pin for the elasticity of spring is used in the one end of ejector pin, because the other end of ejector pin supports and leans on the face of unblocking, makes the valve rod top push ejector pin can make the spring compression, and the changeover portion makes the ejector pin remove smoothly, improves the unblock convenience of hydraulic lock from this.

In the reversing valve, the direction from the pressure release hole self-locking seat to the valve rod gradually inclines towards the wall surface of the transition section. When the valve rod pushes away the lock core, the pressure release hole releases the pressure, the orifice of the pressure release hole is kept away from the ejector pin through the position setting to the pressure release hole, the pressure impact ejector pin when the pressure release hole releases the pressure is avoided, the sinking and dropping amount of the oil cylinder in a pressure maintaining state is reduced, and meanwhile the unlocking convenience of the hydraulic lock is further improved.

In the reversing valve, the ejector rod is sleeved with a positioning piece which is annular and is attached to the transition section, the positioning piece is provided with oil passing holes for oil to pass through, and the number of the oil passing holes is at least two and is arranged at intervals along the circumferential direction of the ejector rod. Because of the setting element cover establish on the ejector pin and paste the changeover portion setting for the setting element plays the effect of location to the ejector pin, and then makes the ejector pin the route that removes in the changeover portion be definite, and the setting of crossing the oilhole makes fluid can pass through the changeover portion, will cross the oilhole and set up along ejector pin circumference interval, and the at utmost avoids the setting element part to receive fluid to strike and take place crooked, so that the removal of ejector pin takes place the jamming, guarantees the unblock convenience of hydraulic lock from this.

In the reversing valve, the valve rod is provided with an unlocking groove for the ejector rod to extend into, the unlocking surface is the groove wall of the unlocking groove and is obliquely arranged, the end surface of the ejector rod is a spherical surface capable of being abutted against the unlocking surface, and a gap is formed between the spherical surface and the bottom of the unlocking groove. Stretch into the structure of unblock groove with the ejector pin to the cell wall of unblock groove is the unblock face, and with the slope setting of unblock face, makes the removal through the valve rod can make the sphere contact unblock face, makes the horizontal migration of valve rod change the vertical removal of valve rod from this, and the clearance between sphere and the unblock groove tank bottom avoids the ejector pin to obstruct the removal of valve rod. Simultaneously, through sphere and unblock face contact for be the point contact between valve rod and the ejector pin, area of contact between them is reduced to this structure, and furthest avoids the ejector pin to take place the incline along with the valve rod removes, guarantees the unblock convenience of hydraulic pressure lock from this.

In the reversing valve, the valve body is provided with a connecting hole, and the lock seat is in threaded connection with the connecting hole. The lock seat and the valve body are firmly connected by the screw connection.

In foretell reversing valve, the annular groove has been seted up on the surface of choked flow portion, seal assembly includes retaining ring and the sealing washer of making by rubber materials, the sealing washer passes through the retaining ring and is positioned in the annular groove, and the sealing washer supports and leans on the pore wall of mounting hole. The setting up of annular groove reduces the fit clearance of choked flow portion and mounting hole on the one hand, on the other hand is convenient for add the retaining ring, make the firm location of sealing washer in the annular groove through the retaining ring, avoid the sealing washer to deviate from the annular groove when choked flow portion removes as far as possible, the sealing washer supports and leans on the mounting hole pore wall, the fit clearance of choked flow portion with the mounting hole has been filled, the leakproofness in spring chamber has been improved, the influence of the pressure of separation promotion hydro-cylinder to the spring chamber, improve the unblock convenience of hydraulic pressure lock from this.

Compared with the prior art, the reversing valve provided by the invention has the following advantages:

1. when the valve rod moves from the middle position to the descending position, the unlocking surface pushes the lock cylinder along with the movement of the valve rod, the lock cylinder overcomes the elasticity of the spring to move relative to the lock seat, and the pressure relief hole is synchronously relieved for the valve rod directly drives the lock cylinder to move, so that the working oil inlet is communicated with the main oil way through the oil inlet way, the sedimentation amount of the lifting oil cylinder is reduced, and the unlocking convenience of the hydraulic lock is improved.

2. The diameter of the transition section is consistent with the aperture of the mounting hole, so that the valve rod can push the lock cylinder to move only by overcoming the elastic force of the spring acting on the lock cylinder, and the unlocking convenience of the hydraulic lock is further improved.

3. One end of the lock cylinder is positioned through the wall of the mounting hole, the wall of the mounting hole guides the movement of the lock cylinder, the other end of the lock cylinder is positioned on the transition section through the positioning piece, the structure reduces the possibility that the lock cylinder is inclined when the valve rod moves through the unlocking surface to push the lock cylinder to avoid the clamping stagnation of the movement of the lock cylinder, and therefore the unlocking convenience of the hydraulic lock is guaranteed.

Drawings

FIG. 1 is a schematic view of the valve stem of the reversing valve in a neutral position.

Figure 2 is an enlarged view of a portion of the present diverter valve of figure 1.

Fig. 3 is an enlarged view of fig. 2.

Fig. 4 is an enlarged view of a portion of the valve stem of the reversing valve in the raised position.

FIG. 5 is an enlarged view of a portion of the valve stem of the reversing valve in the lowered position.

Fig. 6 is a schematic view of a connection structure between a lock cylinder and a positioning element in the first embodiment.

Fig. 7 is a bottom view of fig. 6.

Fig. 8 is a schematic view of a connection structure between the lock cylinder and the positioning element in the second embodiment.

In the figure, 1, hydraulic lock; 11. a spring; 12. a lock seat; 121. mounting holes; 13. a lock cylinder; 131. a pressure relief vent; 132. a flow-impeding portion; 133. a top rod; 134. an accommodation hole; 135. an annular groove; 14. a spring cavity; 15. a positioning member; 151. an oil passing hole; 2. a valve stem; 21. an unlocking groove; 211. unlocking the surface; 212. opening the noodles; 3. a valve body; 31. a working oil inlet; 32. a main oil passage; 33. an oil inlet path; 331. a flow guide section; 332. a transition section; 34. connecting holes; 4. a seal assembly; 41. a retainer ring; 42. and (5) sealing rings.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Example one

As shown in fig. 1, the reversing valve comprises a hydraulic lock 1, a valve rod 2 and a valve body 3 with a working oil inlet 31 and a main oil path 32, wherein the valve rod 2 is provided with an unlocking surface 211 and movably arranged in the main oil path 32 in a penetrating way. As shown in fig. 2 and 3, the hydraulic lock 1 includes a spring 11, a lock base 12 fixed in the valve body 3, and a lock cylinder 13 having an elongated shape and located between a working oil inlet 31 and a main oil passage 32. The valve rod 2 is provided with an unlocking groove 21 for the ejector rod 133 to extend into, the unlocking groove 21 is in a contraction shape from the groove opening to the groove bottom, one side groove wall of the unlocking groove 21 is an unlocking surface 212, the other side groove wall of the unlocking groove 21 is an unlocking surface 211, the unlocking surface 212 and the unlocking surface 211 are both obliquely arranged, one end face of the lock cylinder 13 is a spherical surface capable of abutting against the unlocking surface 211 or the unlocking surface 212, and a gap is formed between the spherical surface and the groove bottom of the unlocking groove 21.

As shown in fig. 2 to 5, a connection hole 34 is formed in the valve body 3, the lock base 12 is screwed with the connection hole 34, the lock base 12 has a mounting hole 121, an accommodation hole 134 is formed at one end of the lock cylinder 13, the lock cylinder 13 is inserted into the mounting hole 121, so that the accommodation hole 134 and the mounting hole 121 enclose a closed spring cavity 14, and the other end of the lock cylinder 13 can abut against an unlocking surface 211. A sealing assembly 4 which radially positions the lock cylinder 13 and seals the spring cavity 14 is arranged between the connecting head and the mounting hole 121. The sealing assembly 4 includes a retainer ring 41 and a sealing ring 42 made of a rubber material, an annular groove 135 is formed on the outer surface of the flow blocking portion 132, the sealing ring 42 is positioned in the annular groove 135 through the retainer ring 41, and the sealing ring 42 abuts against the hole wall of the mounting hole 121.

The spring 11 is located in the spring chamber 14 with one end of the spring 11 abutting against the hole bottom of the accommodation hole 134 and the other end abutting against the hole bottom of the mounting hole 121. The valve body 3 is provided with an oil inlet path 33 communicating the working oil inlet 31 and the main oil path 32, the oil inlet path 33 is provided with a flow guide section 331 and a transition section 332, the flow guide section 331 is communicated with the main oil path 32 through the transition section 332, the lock cylinder 13 is provided with a flow blocking portion 132 positioned on the flow guide section 331, one side of the flow blocking portion 132 is embedded into the mounting hole 121, and the other side of the flow blocking portion 132 can seal the opening of the transition section 332, as shown in fig. 6, the flow blocking portion 132 is provided with a pressure relief hole 131 communicating the spring cavity 14 and the transition section 332, the pressure relief hole 131 is a straight hole, and the diameter of the transition section 332 is the same as the aperture of the mounting hole 121.

The lock core 13 further has a top rod 133 penetrating the transition section 332, one end of the top rod 133 is connected to the flow blocking portion 132, and the other end of the top rod 133 can abut against the unlocking surface 211, as shown in fig. 6 and 7, a positioning member 15 which is annular and abuts against the transition section 332 is sleeved on the top rod 133, oil passing holes 151 for passing oil are formed in the positioning member 15, and the number of the oil passing holes 151 is at least two and is circumferentially spaced along the top rod 133.

When the valve rod 2 is in the lifting position, the spherical surface of the lock cylinder 13 abuts against the opening surface 212, the spring 11 is in a compressed state, and oil flows into the lifting oil cylinder from the main oil path 32 through the working oil inlet 31, so that the lifting of the agricultural machine is realized. After the agricultural machine is lifted to a required position, the valve rod 2 moves to a middle position, the valve rod 2 resets under the elastic force action of the spring 11, so that the flow blocking part 132 cuts off the flow guide section 331 and the transition section 332, oil is prevented from flowing back to the main oil path 32 from the oil cylinder through the working oil inlet 31, and the lifting oil cylinder is in a pressure maintaining state at the moment. The valve rod 2 is moved to a descending position, the spherical surface of the lock cylinder 13 abuts against the unlocking surface 211, the spring 11 is in a compressed state, and the oil flows back to the main oil path 32 from the oil cylinder through the working oil inlet 31, so that the descending of the agricultural machine is realized.

Example two

As shown in fig. 8, the structure and principle of the present embodiment are substantially the same as those of the first embodiment, except that in the present embodiment, the pressure relief hole 131 is gradually inclined toward the wall surface of the transition section 332 from the lock base 12 to the valve stem 2.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Although terms such as the hydraulic lock 1, the spring 11, the lock base 12, the mounting hole 121, the lock cylinder 13, the relief hole 131, the flow blocking portion 132, the plunger 133, the receiving hole 134, the annular groove 135, the spring cavity 14, the positioning member 15, the oil passing hole 151, the valve rod 2, the unlocking groove 21, the unlocking surface 211, the opening surface 212, the valve body 3, the working oil inlet 31, the main oil passage 32, the oil inlet passage 33, the flow guide section 331, the transition section 332, the connecting hole 34, the seal assembly 4, the retainer ring 41, and the seal ring 42 are used more frequently, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

Claims

1. A reversing valve comprises a hydraulic lock (1), a valve rod (2) and a valve body (3) with a working oil inlet (31) and a main oil way (32), wherein the valve rod (2) is provided with an unlocking surface (211) and movably penetrates through the main oil way (32), the hydraulic lock (1) comprises a spring (11) and a lock seat (12) fixedly connected in the valve body (3), the reversing valve is characterized in that the hydraulic lock (1) further comprises a lock cylinder (13) which is in a long strip shape and is positioned between the working oil inlet (31) and the main oil way (32), one end of the lock cylinder (13) can abut against the unlocking surface (211), a spring cavity (14) is formed by enclosing between the other end of the lock cylinder (13) and the lock seat (12), the spring (11) is positioned in the spring cavity (14) and the end part of the spring abuts against the lock seat (12) and the lock cylinder (13) elastically, a pressure relief hole (131) for communicating the spring cavity (14) with the main oil way (32) and the main oil way (13) is formed in the lock cylinder (13), when the valve rod (2) is located at the middle position, the lock cylinder (13) separates the working oil inlet (31) and the main oil way (32) under the elastic force action of the spring (11), and when the valve rod (2) moves to enable the lock cylinder (13) to overcome the elastic force of the spring (11) to abut against the unlocking surface (211) and enable the pressure relief hole (131) to relieve pressure, the working oil inlet (31) is communicated with the main oil way (32).

2. A reversing valve according to claim 1, characterized in that the lock housing (12) has a mounting hole (121), the lock cylinder (13) is inserted into the mounting hole (121) to form the spring chamber (14), and a sealing assembly (4) is provided between the lock cylinder (13) and the mounting hole (121) for radially positioning the lock cylinder (13) and sealing the spring chamber (14).

3. The reversing valve according to claim 2, wherein the valve body (3) is provided with an oil inlet path (33) communicating the working oil inlet (31) and the main oil path (32), the oil inlet path (33) is provided with a flow guide section (331) and a transition section (332), the flow guide section (331) is communicated with the main oil path (32) through the transition section (332), the lock cylinder (13) is provided with a flow blocking part (132) positioned on the flow guide section (331), one side of the flow blocking part (132) is embedded into the mounting hole (121), and the other side of the flow blocking part (132) can block the transition section (332).

4. A direction-changing valve according to claim 3, wherein the flow blocking portion (132) is provided with the pressure relief hole (131), the pressure relief hole (131) communicates with the spring cavity (14) and the transition section (332), and the diameter of the transition section (332) is the same as the diameter of the mounting hole (121).

5. The reversing valve according to claim 3 or 4, characterized in that one side of the flow blocking portion (132) embedded in the mounting hole (121) is provided with a receiving hole (134), one end of the spring (11) abuts against the bottom of the receiving hole (134), the other end of the spring abuts against the bottom of the mounting hole (121), the lock cylinder (13) is further provided with a push rod (133) penetrating into the transition section (332), one end of the push rod (133) is connected with the flow blocking portion (132), and the other end of the push rod (133) can abut against the unlocking surface (211).

6. A reversing valve according to claim 3 or 4, characterized in that the direction from the locking seat (12) to the valve stem (2) of the pressure relief opening (131) is inclined gradually towards the wall of the transition section (332).

7. The reversing valve according to claim 5, characterized in that the ejector rod (133) is sleeved with a ring-shaped positioning piece (15) attached to the transition section (332), the positioning piece (15) is provided with oil passing holes (151) for oil to pass through, and the number of the oil passing holes (151) is at least two and is arranged at intervals along the circumferential direction of the ejector rod (133).

8. The reversing valve according to claim 5, characterized in that the valve rod (2) is provided with an unlocking groove (21) into which the ejector rod (133) extends, the unlocking surface (211) is a groove wall of the unlocking groove (21), the unlocking surface (211) is obliquely arranged, the end surface of the ejector rod (133) is a spherical surface capable of abutting against the unlocking surface (211), and a gap is formed between the spherical surface and a groove bottom of the unlocking groove (21).

9. A reversing valve according to claim 1 or 2, characterized in that the valve body (3) is provided with a connecting hole (34), and the lock base (12) is in threaded connection with the connecting hole (34).

10. A reversing valve according to claim 3 or 4, characterized in that an annular groove (135) is formed in the outer surface of the flow blocking portion (132), the sealing assembly (4) comprises a retaining ring (41) and a sealing ring (42) made of rubber material, the sealing ring (42) is positioned in the annular groove (135) through the retaining ring (41), and the sealing ring (42) abuts against the wall of the mounting hole (121).