Direct control type power valve

Abstract

The utility model discloses a direct control type power valve which comprises a valve body provided with an oil duct inner hole and an oil drainage cavity, a valve sleeve is arranged in the oil duct inner hole of the valve body in a sliding mode, an annular groove P and an annular groove A are formed in the cylindrical surface of the valve sleeve at intervals, and the annular groove P is normally communicated with the oil duct inner hole. The inner wall of the annular groove P and the inner wall of the annular groove A are each provided with at least one through hole communicating with an inner cavity of the valve sleeve. The valve core is slidably arranged in the valve sleeve, two ends of the valve core extend out of the valve sleeve, shoulders at the left end and the right end of the valve core are unequal in diameter, and the shoulders on the two sides of the valve core slide to realize on-off and flow control of the through holes in the annular grooves P and A; a plug for limiting the movement of the valve core is arranged at one end, with smaller diameter, of the valve core, and an elastic component for limiting the movement of the valve core is arranged at the other end of the valve body; a shifting fork is rotationally arranged on the valve body, and a variable plunger of the plunger pump is movably connected with the valve sleeve through the shifting fork. The constant power control of the plunger pump can be realized, the structure of the constant power control module is simplified, the manufacturing cost is reduced, and the application and popularization of the plunger pump are facilitated.

Description

Technical Field

[0001] The utility model relates to a direct control type power valve, belonging to the technical field of hydraulic piston pumps. Background Art

[0002] As an important control unit of the piston pump, the main function of the constant power valve is to receive the external load pressure signal, and automatically adjust the output flow rate of the piston pump according to the external load signal, so that the product power p of the output flow rate Q of the piston pump and the external load pressure signal P is always lower than the output power of the engine, ensuring that the engine will not be in an overloaded working state, thereby causing the whole machine to stall or flameout.

[0003] It can be seen from the constant power calculation formula p = P×Q that when the piston pump enters the constant power control, at a certain load pressure value, the output flow rate Q of the piston pump is a certain fixed value, ensuring that the product of the two is the set constant power value p. Then when the load changes, the output flow rate of the piston pump should change accordingly to ensure that the product is fixed.

[0004] Traditional constant power control is usually indirect control. The structure is as Figure 1 、 2 shown, and the constant power control is realized by combining two independent valve assemblies. Figure 1 is valve assembly A, Figure 2 is valve assembly B, and the process of realizing constant power control is as follows: In valve assembly A, the load pressure signal P acts on the two shoulder end faces of the spool one through the oil passage. The structure of the spool one is as Figure 3 shown. The diameters of the left and right shoulders of the spool one are different, with the left side larger than the right side. Secondly, a brow groove is opened on the column surface of the left shoulder. The hydraulic oil P acts on the shoulder end face of the spool one. Since the area on the left side is larger than the area on the right side, when the spool one overcomes the spring force on the left side, the spool one moves to the left. At this time, the valve sleeve one is always attached to the feedback pin column surface of the variable rocker under the action of the return spring one. Since the piston pump has not been variable, the variable rocker does not rotate, and the valve sleeve one is restricted from moving to the left. When the spool one overcomes the spring and moves to the left, the column surface brow groove cannot be sealed by the inner hole column surface of the valve sleeve one, and the hydraulic oil P acting in the shoulder will be instantaneously communicated with the oil drain cavity T, and the acting load oil pressure P drops to P1.

[0005] As Figure 2Shown is the valve assembly B. On its right side is the load hydraulic oil P separately introduced by the oil passage, and on its left side is the oil passage communicating with the load pressure oil P acting on the two shoulders of the spool. Since a throttle screw is installed between the separately introduced load oil pressure P on the right side and the load pressure oil P acting on the two shoulders of the spool, when the spool two moves leftward to relieve pressure, the hydraulic oil P between the two shoulders of the spool two will instantaneously drop to P1. Due to the existence of the throttle screw, the separately introduced load hydraulic oil P on the right side of the valve assembly B will not change significantly. For the valve assembly B, since the P on the left side drops to P1 and the P on the right side remains unchanged, when the hydraulic pressure of P on the right side generates a leftward hydraulic force on the spool two that is greater than the sum of the rightward hydraulic force generated by P1 on the left side on the spool two and the spring force, the spool two in the valve assembly B moves leftward, controlling the oil pressure P to enter the control oil passage A, realizing the constant power variable control of the piston pump.

[0006] It can be seen that to achieve constant power control, the valve assembly A and the valve assembly B need to cooperate together. The valve assembly A and the valve assembly B receive the pressure signal P and cannot achieve constant power control alone. This indirect power control method not only has a complex structure, many types of parts, high manufacturing costs, but also has high requirements for the machining accuracy of parts, restricting the development of the application of constant power control of piston pumps.

[0007] Therefore, there is an urgent need in the technical field to develop a direct control type constant power valve, which can not only meet the control requirements of constant power characteristics, but also optimize the structure, reduce the types of parts, lower the machining accuracy of parts, optimize the production and manufacturing costs, and promote the development of the constant power control method of piston pumps. Summary of the Utility Model

[0008] The technical problem to be solved by the present utility model is the problem that the indirect constant power control of the existing piston pump brings about a complex overall structure, many types of parts, strict machining accuracy, high manufacturing costs, which restricts the application development of the constant power control method of the piston pump.

[0009] To solve the above technical problems, the present utility model provides a direct control type power valve, which can not only meet the control requirements of constant power characteristics, but also optimize the structure, reduce the types of parts, lower the machining accuracy of parts, optimize the production and manufacturing costs, and promote the development of the constant power control method of piston pumps.

[0010] To achieve the above technical purpose and reach the above technical effect, the present application is realized through the following technical solutions:

[0011] A direct-controlled power valve comprises a valve body, which is provided with an inner hole of an oil passage and an oil leakage cavity, and also comprises a valve sleeve and a valve core, wherein the valve sleeve is slidably arranged in the inner hole of the oil passage of the valve body, an annular groove P and an annular groove A are spaced apart on the cylindrical surface of the valve sleeve, the annular groove P is always connected with the inner hole of the oil passage, and at least one through hole connected with the inner cavity of the valve sleeve is opened on the inner wall of the annular groove P and the annular groove A around the circumferential direction; the valve core is slidably arranged in the valve sleeve and both ends extend out of the valve sleeve, the diameters of the shoulders at the left and right ends of the valve core are different, the inner diameter of the valve sleeve is adapted to the valve core, and the shoulders on both sides of the valve core realize the on-off and flow control of the through holes on the annular groove P and the annular groove A by sliding; a screw plug for limiting the movement of the valve core is provided at the end of the valve body located at the smaller diameter of the valve core, and an elastic component for limiting the movement of the valve core is provided at the end of the valve body located at the larger diameter of the valve core;

[0012] A shift fork is rotatably arranged on the valve body, one end of the shift fork is movably connected to the outer wall of one end of the valve sleeve away from the screw plug, and the other end of the shift fork extends out of the valve body to connect with the variable plunger of the plunger pump.

[0013] Preferably, the elastic component includes a nut, a large spring, a support rod, a small spring and a spring seat, the nut is detachably connected to the valve body, the spring seat is slidably arranged in the inner hole of the oil channel, the large spring is pressed between the nut and the spring seat and pushes the spring seat to abut against the end face of the valve core, the support rod is arranged at one end of the nut extending into the inner hole of the oil channel and extending into the large spring, and the small spring is pressed between the support rod and the spring seat.

[0014] Furthermore, an external thread is provided on the outer wall of the nut, and the nut is threadedly connected to the inner hole of the oil channel through the external thread, and the length of the external thread is greater than the length of the part in the inner hole of the oil channel that is threaded with the nut.

[0015] Furthermore, the support rod is slidably arranged in the nut along the axial direction of the valve core, and the support rod and the nut are matched with a small gap. An adjusting screw for adjusting the distance between the support rod and the spring seat is threaded through one end of the nut away from the valve body.

[0016] Furthermore, the nut is externally threadedly connected with a large locking nut that tightens the nut and the valve body, and the adjusting screw is externally threadedly connected with a small locking nut that tightens the nut and the adjusting screw.

[0017] Furthermore, the valve core and the valve sleeve are matched with a small gap, a convex arc is provided on one end of the valve core facing the spring seat, and a concave arc matched with the convex arc is provided on the spring seat.

[0018] Preferably, the shift fork is rotatably arranged on the valve body through pin body 1, one end of the shift fork connected to the valve sleeve is detachably connected with pin body 2, and a waist-shaped groove movably plugged with pin body 2 is provided on the outer wall of the valve sleeve.

[0019] Furthermore, O-rings are embedded on the outer walls of the screw plug, the nut and the support rod.

[0020] The direct control type power valve provided by the present utility model has the following advantages:

[0021] While realizing the constant power control characteristic, the direct control type constant power valve of the present utility model can also optimize the structure, reduce the types of parts, lower the machining precision of parts, optimize the production and manufacturing cost, and promote the development of the constant power control mode of the plunger pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the traditional indirect constant power control valve assembly A;

[0023] Figure 2 is a schematic structural diagram of the traditional indirect constant power control valve assembly B;

[0024] Figure 3 is a structural diagram of the valve core of the valve assembly A;

[0025] Figure 4 is a schematic structural diagram of a direct control type power valve of the present utility model;

[0026] Figure 5 is a schematic structural diagram of the valve sleeve of a direct control type power valve of the present utility model;

[0027] In the figure:

[0028] 1 - valve body; 2 - valve sleeve; 21 - through hole; 22 - kidney-shaped groove; 3 - valve core; 4 - elastic component; 41 - nut; 411 - external thread; 42 - large spring; 43 - support rod; 44 - small spring; 45 - spring seat; 5 - screw plug; 6 - fork; 7 - adjusting screw; 8 - large locking nut; 9 - small locking nut; 10 - pin body one; 11 - pin body two; 12 - O-ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present utility model.

[0030] Referring to Figure 4 and Figure 5 , a direct control type power valve includes a valve body 1. An oil passage inner hole and an oil drain cavity are provided on the valve body 1 to realize the circulation of high-pressure oil, which is the prior art and will not be elaborated too much.

[0031] Further, a direct control type power valve further includes a valve sleeve 2 and a valve core 3. The valve sleeve 2 is slidably installed in the inner hole of the oil passage of the valve body 1, and a small clearance fit is provided between the outer circle of the valve sleeve 2 and the inner hole of the oil passage of the valve body 1 to ensure that the valve sleeve 2 can move flexibly within the valve body 1. Annular grooves P and annular grooves A are spaced apart on the cylindrical surface of the valve sleeve 2 for oil passage. The annular groove P is always communicated with the inner hole of the oil passage. At least one through hole 21 communicating with the inner cavity of the valve sleeve 2 is provided around the circumferential direction on the inner walls of the annular groove P and the annular groove A. The valve core 3 is slidably inserted into the valve sleeve 2 and extends out of the valve sleeve 2 at both ends. The diameters of the shoulders at the left and right ends of the valve core 3 are not equal. The inner diameter of the valve sleeve 2 is adapted to the valve core 3. The shoulders on both sides of the valve core 3 control the on-off and flow rate of the through hole 21 on the annular groove P and the annular groove A through sliding. A plug 5 for restricting the movement of the valve core 3 is threadedly locked at the end of the valve body 1 where the diameter of the valve core 3 is smaller, and an elastic force assembly 4 for restricting the movement of the valve core 3 is installed at the end of the valve body 1 where the diameter of the valve core 3 is larger.

[0032] Further, a fork 6 is rotatably installed on the valve body 1. One end of the fork 6 is movably connected to the outer wall of the valve sleeve 2 away from the plug 5, and the other end of the fork 6 extends out of the valve body 1 and is provided with a point C groove to connect the variable plunger of the plunger pump.

[0033] Refer to Figure 1 , in a further embodiment, a small clearance fit is provided between the valve core 3 and the valve sleeve 2. A convex arc is integrally formed at one end of the valve core 3 facing the spring seat 45, and a concave arc adapted to the convex arc is provided on the spring seat 45 to ensure the flexible movement of the valve core 3.

[0034] Refer to Figure 4 , the elastic force assembly 4 includes a nut 41, a large spring 42, a support rod 43, a small spring 44 and a spring seat 45. The nut 41 is detachably connected to the valve body 1. The spring seat 45 is slidably installed in the inner hole of the oil passage. The large spring 42 is pressed between the nut 41 and the spring seat 45. The spring seat 45 abuts against the end face of the valve core 3 under the elastic force of the large spring 42. The support rod 43 is installed at one end of the nut 41 extending into the inner hole of the oil passage and extends into the large spring 42. The small spring 44 is pressed between the support rod 43 and the spring seat 45.

[0035] Further, an external thread 411 is integrally formed on the outer wall of the nut 41. The nut 41 is threadedly connected to the inner hole of the oil passage through the external thread 411, and the length of the external thread 411 is greater than the length of the part of the inner hole of the oil passage screwed with the nut 41. Furthermore, the pre-pressure of the large spring 42 can be adjusted by controlling the screwing distance between the nut 41 and the valve body 1.

[0036] Further, the support rod 43 is axially slidably installed in the nut 41 along the valve core 3, and there is a small clearance fit between the support rod 43 and the nut 41 to ensure that the support rod 43 can move flexibly. One end of the nut 41 facing away from the valve body 1 is threadedly penetrated with an adjusting screw 7 for adjusting the distance between the support rod 43 and the spring seat 45. During use, the pre-pressure of the small spring 44 can be adjusted by screwing the adjusting screw 7.

[0037] Referring to Figure 4 , a large locking nut 8 for clamping the nut 41 and the valve body 1 is externally screwed on the nut 41, and a small locking nut 9 for clamping the nut 41 and the adjusting screw 7 is externally screwed on the adjusting screw 7. Thus, it can effectively prevent the nut 41 and the adjusting screw 7 from loosening, maintain the fastening force, reduce vibration, improve the connection strength, and ensure the stability and safety of the machine.

[0038] Referring to Figure 4 , in a further embodiment, the fork 6 is rotatably installed on the valve body 1 through a pin body one 10. One end of the fork 6 connected to the valve sleeve 2 is fixedly inserted with a pin body two 11 in an interference fit. A waist-shaped groove 22 for movably inserting the pin body two 11 is opened on the outer wall of the valve sleeve 2, so that the fork 6 and the valve sleeve 2 can be movably connected.

[0039] Referring to Figure 4 , in a further embodiment, O-rings 12 are embedded on the outer walls of the plug 5, the nut 41 and the support rod 43 to seal the whole structure.

[0040] Taking the right side of the valve core 3 as the larger diameter end as an example, the working principle of a direct control type power valve of the present invention is as follows:

[0041] The load high-pressure oil reaches the annular groove P on the valve sleeve 2 through the oil passage, and acts on the two shoulders of the valve core 3 through the through hole 21 on the annular groove. Since the diameter of the right side of the valve core 3 is larger than that of the left side, the external load pressure oil generates a rightward acting force on the valve core 3. Since the diameters of the left and right shoulders of the valve core 3 are different, the diameters of the inner holes of the valve sleeve 2 are also different. While the load pressure oil P generates a rightward acting force on the valve core 3, it generates a leftward hydraulic pressure on the valve sleeve 2. The point C groove on the fork 6 is matched with the variable plunger through a pin. Since the plunger pump has not been variable at this time and the variable plunger has not moved, with the pin body one 10 as the fulcrum and the valve sleeve 2 being restricted by the pin body two 11, the valve sleeve 2 remains stationary.

[0042] When the hydraulic pressure overcomes the pre-pressures of the adjusting screw 7 and the nut 41 on the small spring 44 and the large spring 42, the valve core 3 moves to the right, and the high-pressure oil at the P port of the annular groove is connected to the oil passage through hole 21 of the A port of the annular groove. The load oil acts on the variable chamber, and the plunger pump starts variable control.

[0043] The nut 41 and the adjusting screw rod 7 can adjust the pre-pressure of the large and small springs 44, thereby controlling the load pressure when the oil port P is connected to A. The connected load pressure is also the starting point of the constant power control variable.

[0044] It can be seen that compared with the traditional indirect constant power control method, this constant power control method not only has a simple structure, fewer types of parts, but also significantly reduces the manufacturing cost.

[0045] The oil passage on the left side of the flow control valve core 3 is the load oil pressure, which acts on the right end of the flow control valve core 3 through the small holes inside the flow control valve core 3. The plug 5 seals the load oil pressure, and the load oil pressure in the inner hole of the oil passage generates a hydraulic pressure acting on the valve core 3 to the left.

[0046] As described above, it is only the preferred embodiment of the present invention, and it is not a limitation to any form and essence of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the premise of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any equivalent changes made by those skilled in the art who are familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above, such as slight modifications, decorations, and evolutions, are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A direct control type power valve, comprising a valve body (1), wherein an oil passage inner hole and an oil drain cavity are provided on the valve body (1), and it is characterized in that, It also comprises a valve sleeve (2) and a valve core (3), wherein the valve sleeve (2) is slidably arranged in the inner hole of the oil passage of the valve body (1), an annular groove P and an annular groove A are spaced apart on the cylindrical surface of the valve sleeve (2), the annular groove P is in communication with the inner hole of the oil passage, and at least one through hole (21) in communication with the inner cavity of the valve sleeve (2) is formed on the inner wall of the annular groove P and the annular groove A in a circumferential direction; the valve core (3) is slidably arranged in the valve sleeve (2) and both ends of the valve core (3) extend out of the valve sleeve (2). 2), the diameters of the shoulders at the left and right ends of the valve core (3) are different, the inner diameter of the valve sleeve (2) is adapted to the valve core (3), and the shoulders at both sides of the valve core (3) achieve the on-off and flow control of the annular groove P and the through hole (21) on the annular groove A by sliding; a screw plug (5) for limiting the movement of the valve core (3) is provided at the end of the valve body (1) where the diameter of the valve core (3) is smaller, and an elastic component (4) for limiting the movement of the valve core (3) is provided at the end of the valve body (1) where the diameter of the valve core (3) is larger; A shift fork (6) is rotatably arranged on the valve body (1), one end of the shift fork (6) being movably connected to the outer wall of one end of the valve sleeve (2) away from the screw plug (5), and the other end of the shift fork (6) extending out of the valve body (1) to connect to the variable displacement plunger of the plunger pump.

2. The direct control type power valve according to claim 1, characterized in that, The elastic component (4) comprises a nut (41), a large spring (42), a support rod (43), a small spring (44) and a spring seat (45); the nut (41) is detachably connected to the valve body (1); the spring seat (45) is slidably arranged in the inner hole of the oil passage; the large spring (42) is pressed between the nut (41) and the spring seat (45) and pushes the spring seat (45) to abut against the end surface of the valve core (3); the support rod (43) is arranged at one end of the nut (41) extending into the inner hole of the oil passage and extending into the large spring (42); and the small spring (44) is pressed between the support rod (43) and the spring seat (45).

3. The direct control type power valve according to claim 2, characterized in that, An external thread (411) is provided on the outer wall of the nut (41), and the nut (41) is threadedly connected to the inner hole of the oil passage through the external thread (411), and the length of the external thread (411) is greater than the length of the threaded connection portion of the inner hole of the oil passage and the nut (41).

4. The direct control type power valve according to claim 3, characterized in that, The support rod (43) is slidably arranged in the nut (41) along the axial direction of the valve core (3), and the support rod (43) and the nut (41) are matched with a small gap. An adjusting screw (7) for adjusting the distance between the support rod (43) and the spring seat (45) is threadedly penetrated at one end of the nut (41) away from the valve body (1).

5. The direct control type power valve according to claim 4, wherein, The nut (41) is externally threadedly connected with a large locking nut (8) that tightens the nut (41) and the valve body (1), and the adjusting screw (7) is externally threadedly connected with a small locking nut (9) that tightens the nut (41) and the adjusting screw (7).

6. The direct control type power valve according to claim 2, characterized in that, The valve core (3) and the valve sleeve (2) are matched with each other with a small gap, and a convex arc is arranged at one end of the valve core (3) facing the spring seat (45), and a concave arc matching the convex arc is arranged on the spring seat (45).

7. The direct control type power valve according to claim 1, characterized in that, The shift fork (6) is rotatably arranged on the valve body (1) through a first pin body (10), and a second pin body (11) is detachably connected to one end of the shift fork (6) connected to the valve sleeve (2). A kidney-shaped groove (22) for movably inserting the second pin body (11) is formed in the outer wall of the valve sleeve (2).

8. The direct control type power valve according to claim 4, wherein O-rings (12) are embedded on the outer walls of the plug (5), the nut (41) and the support rod (43).

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