Variable pump flow control device

Abstract

The utility model relates to a variable pump flow control device which comprises a flow control valve which is in positioning connection with a variable pump through a transition plate. The flow control valve is composed of a valve body, a valve sleeve arranged in an inner cavity of the valve body, a valve element matched with the valve sleeve, a protection component matched with the right end of the valve element and an adjusting rod abutting against the left end of the valve element, the protection component is fixedly connected to the right end of the valve body through a right end cover, and the adjusting rod is fixedly connected to the left end of the valve body through a left end cover. The transition component comprises a transition plate, the flow control valve is fixed to the transition plate through a plurality of first screws, and the transition plate is fixed to the variable pump through a plurality of second screws. The flow control valve is provided with an oil return port butt joint port, a first valve element oil port, a second valve element oil port, a first damping oil port and a second damping oil port which are communicated with an inner cavity of the valve body, and the flow control valve is communicated with an oil inlet and an oil outlet of the variable pump after being guided through the transition plate. Whether flow needs to be cut off can be automatically judged according to the output pressure of the hydraulic pump, and the working stability of a hydraulic system is guaranteed.

Description

Technical Field

[0001] The utility model relates to a hydraulic pump, and mainly relates to a flow control device for a variable pump. This control device can be widely used in hydraulic pumps. Background Technique

[0002] During the use of hydraulic construction machinery, there is often a phenomenon that the pressure exceeds the set limit value, thus there are potential safety hazards. To solve the problems existing in the hydraulic pump, CN 207131649U discloses "a flow control device for an integrated fixed-displacement motor variable pump", which includes a flow regulation mechanism and a neutral damping limit mechanism that can accurately return the flow regulation mechanism to the middle position during actual work. The flow regulation mechanism includes a turntable, a valve sleeve, a valve body, and a rotating shaft. The rotating shaft is rotatably inserted and installed in the valve sleeve. The rotating shaft and the valve sleeve are vertically arranged in the valve body. The turntable is arranged above the valve body and is fixedly clamped and installed at the upper end of the rotating shaft. The neutral damping limit mechanism is fixedly arranged on one side of the valve body and corresponds to the turntable.

[0003] In addition, CN211422895U also discloses "a variable pump with a flow control device". It solves the problem that the neutral output flow control of the existing variable pump is inaccurate, resulting in inaccurate flow output of the variable pump during work. It includes a housing, a pump drive shaft and a rotor assembly are arranged in the housing. The rotor assembly includes a cylinder block, a rotating disk, a swinging member for limiting the rotating disk, and a plunger for sucking and discharging oil that is adapted to the cylinder block. The pump drive shaft is connected to the cylinder block and drives the rotating disk to rotate through the cylinder block. A neutral control mechanism is arranged on the housing. The neutral control mechanism is connected to the swinging member and can drive the swinging member to swing. It sets a neutral control mechanism, which plays a limiting role by connecting with the swinging mechanism, so that the displacement is accurate during the neutral displacement debugging process.

[0004] Undoubtedly, the technical solutions disclosed in the two patent documents are both beneficial attempts in the technical field to which they belong. Content of the Utility Model

[0005] The purpose of the utility model is to provide a flow control device for a variable pump, which can automatically judge whether it is necessary to cut off the flow according to the output pressure of the hydraulic pump. When the output pressure of the hydraulic pump exceeds the set value, it can automatically adjust the output flow to cut off, so as to ensure the working stability of the hydraulic system.

[0006] A flow control device for a variable pump according to the present utility model includes a flow control valve, and the flow control valve is positioned and connected to the variable pump through a transition plate; the flow control valve consists of a valve body, a valve sleeve arranged in the inner cavity of the valve body, a valve core matched with the valve sleeve, a protection member matched with the right end of the valve core, and an adjusting rod closely abutted against the left end of the valve core. The protection member is fixedly connected to the right end of the valve body through a right end cover, and the adjusting rod is fixedly connected to the left end of the valve body through a left end cover; the transition member includes a transition plate, and the flow control valve is fixed to the transition plate by a plurality of first screws, and the transition plate is fixed to the variable pump by a plurality of second screws; the flow control valve is provided with an oil return port docking port, a first valve core oil port, a second valve core oil port, a first damping oil port, and a second damping oil port communicated with the inner cavity of the valve body. After guiding through the transition plate, it is communicated with the oil inlet and outlet ports of the variable pump.

[0007] Further, a small spring and a large spring are sleeved on the right part of the adjusting rod; a baffle is arranged at the right ends of the small spring and the large spring. The baffle is an integral body with the adjusting rod and is closely abutted against the left end of the valve core; an adjusting plate is arranged at the left ends of the small spring and the large spring, and the adjusting plate is closely abutted against the step on the adjusting rod.

[0008] Further, the transition plate of the transition member is provided with a first oil inlet, a second oil inlet, a first control oil port, a second control oil port, and an oil return port of the oil return port docking port; a first valve core oil port docking port communicated with the first control oil port and a second valve core oil port docking port communicated with the second control oil port are also provided. The first valve core oil port docking port is docked with the first valve core oil port, and the second valve core oil port docking port is docked with the second valve core oil port; a first damping oil port docking port communicated with the first damping oil port and a second damping oil port docking port communicated with the second damping oil port are also provided.

[0009] Further, the valve sleeve adopts a multi-section groove structure, and oil through holes are added at each section of the groove to ensure that the pressure oil can flow to both sides of the valve core.

[0010] Further, the valve core is a multi-section variable diameter structure, and the diameters of the left end, the middle part, and the right end are equal. The diameters of the connection sections between the left end and the middle part and between the middle part and the right end are equal and smaller than the diameter of the middle part; the right side surface of the middle part of the valve core is a first stress surface, and the left end surface is a second stress surface.

[0011] Further, dampers are respectively installed at the first valve core oil port and the second valve core oil port.

[0012] Further, both the small spring and the large spring are helical springs, and the large spring is arranged outside the small spring, and the two have the same length.

[0013] Further, the process holes of the oil channels on the transition plate of the transition member are all plugged with first screw plugs.

[0014] Further, the process holes of the oil passages provided on the valve body are all blocked by second screw plugs.

[0015] Advantages of the utility model:

[0016] When the output pressure of the hydraulic pump exceeds the set value, the output flow can be automatically adjusted to cut off, thereby ensuring the working stability of the hydraulic system.

[0017] Since the oil outlet of the variable pump is connected to the oil inlet of the control valve through a transition plate, and the oil outlet of the control valve is connected to the output flow control oil port of the variable pump, it has a high integration degree.

[0018] Since a damper is installed at the oil inlet of the control valve, the unsteady high-pressure hydraulic oil introduced by the transition plate can be converted into steady oil fluid on both sides of the valve core, reducing the pressure impact.

[0019] Since the spring adopts a parallel connection mode of a large spring and a small spring, the spring force generated under the same compression amount is greater.

[0020] Since the adjusting rod is installed on one side of the large spring and the small spring, the spring compression amount can be adjusted by tightening the adjusting rod, thereby changing the pressure required for the valve core to move.

[0021] Since the valve sleeve adopts a multi-segment structure and oil through holes are added at the grooves of each segment, the pressure oil fluid can flow to both sides of the valve core. Brief description of the drawings

[0022] Figure 1 is the structural schematic diagram of the utility model;

[0023] Figure 2 is Figure 1 the top view of

[0024] Figure 3 is Figure 2 the rear view of

[0025] Figure 4 is Figure 1 the A - A cross-sectional view of

[0026] Figure 5 is Figure 2 the B - B cross-sectional view of

[0027] Figure 6 is the structural schematic diagram of the flow control valve;

[0028] Figure 7 is Figure 6 the bottom view of

[0029] Figure 8 is the structural schematic diagram of the valve sleeve;

[0030] Figure 9 It is a structural diagram of the valve core.

[0031] In the figure (technical features indicated by marks):

[0032] 1—valve body, 10—valve sleeve, 11—valve core, 12—baffle, 13—small spring, 14—large spring, 15—adjusting plate, 18—second screw plug;

[0033] 111—first force-bearing surface, 112—second force-bearing surface; 145—oil return port docking port, 146—first valve core oil port, 147—second valve core oil port, 148—first damping oil port, 149—second damping oil port;

[0034] 2—right end cover;

[0035] 3—Protective components;

[0036] 4—transition plate, 41—first oil inlet, 42—second oil inlet, 43—first control oil port, 44—second control oil port, 45—oil return port, 46—first valve core oil port docking port, 47—second valve core oil port docking port, 48—first damping oil port docking port, 49—second damping oil port docking port;

[0037] 5—First screw plug,

[0038] 6—Left end cover,

[0039] 7—Adjustment rod,

[0040] 8—First screw,

[0041] 9—Second screw. DETAILED DESCRIPTION

[0042] The technical solution of the utility model is described in detail below with reference to the accompanying drawings.

[0043] See also Figures 1 to 9A variable pump flow control device shown in the figure includes a flow control valve, and the flow control valve is positioned and connected to the variable pump through a transition plate 4; the flow control valve consists of a valve body 1, a valve sleeve 10 arranged in the inner cavity of the valve body, a valve core 11 that cooperates with the valve sleeve, a protection member 3 that cooperates with the right end of the valve core, and an adjusting rod 7 that abuts against the left end of the valve core. The protection member 3 is fixedly connected to the right end of the valve body 1 through a right end cover 2, and the adjusting rod 7 is fixedly connected to the left end of the valve body 1 through a left end cover 6; the transition member includes a transition plate 4, and the flow control valve is fixed to the transition plate 4 by a plurality of first screws 8, and the transition plate 4 is fixed to the variable pump (not marked in the figure) by a plurality of second screws 9; the flow control valve is provided with an oil return port docking interface 145, a first valve core oil port 146, a second valve core oil port 147, a first damping oil port 148, and a second damping oil port 149 that communicate with the inner cavity of the valve body, and after being guided by the transition plate 4, they are communicated with the oil inlet and outlet ports of the variable pump.

[0044] A small spring 13 and a large spring 14 are sleeved on the right part of the adjusting rod 7; a baffle 12 is provided at the right ends of the small spring 13 and the large spring 14, and the baffle is integral with the adjusting rod 7 and abuts against the left end of the valve core 11; an adjusting plate 15 is provided at the left ends of the small spring 13 and the large spring 14, and the adjusting plate abuts against the step on the adjusting rod 7. Rotating the adjusting rod can move the adjusting plate left and right, thereby modifying the spring forces of the large spring and the small spring.

[0045] The transition plate 4 of the transition member is provided with a first oil inlet 41, a second oil inlet 42, a first control oil port 43, a second control oil port 44, and an oil return port 45 of the oil return port docking interface 145; a first valve core oil port docking interface 46 communicated with the first control oil port 43 and a second valve core oil port docking interface 47 communicated with the second control oil port 44 are also provided. The first valve core oil port docking interface 46 is docked with the first valve core oil port 146, and the second valve core oil port docking interface 47 is docked with the second valve core oil port 147; a first damping oil port docking interface 48 communicated with the first damping oil port 148 and a second damping oil port docking interface 49 communicated with the second damping oil port 149 are also provided.

[0046] The valve sleeve 10 adopts a multi-section groove structure, and oil through holes are added at each section of the groove to ensure that pressure oil can flow to both sides of the valve core 11.

[0047] The valve core 11 is a multi-section variable diameter structure, and the diameters of the left end, the middle part, and the right end are equal. The diameters of the connection sections between the left end and the middle part and between the middle part and the right end are equal and smaller than the diameter of the middle part; the right side surface of the middle part of the valve core 11 is a first stress surface 111, and the left end surface is a second stress surface 112.

[0048] Dampers are respectively installed at the first spool oil port 146 and the second spool oil port 147 to convert the high-pressure and fluctuating hydraulic oil output by the variable pump into stable oil, thereby reducing the pressure shock.

[0049] Both the small spring 13 and the large spring 14 are helical springs. The large spring 14 is arranged outside the small spring 13, and the two have the same length. The parallel connection method of the large and small springs is adopted, so that under the condition of the same compression amount, the generated spring force is greater.

[0050] The process holes of the oil channels provided on the transition plate 4 of the transition member are all blocked by the first plug 5.

[0051] The process holes of the oil channels provided on the valve body 1 are all blocked by the second plug 18.

[0052] The working process of the present utility model:

[0053] When the variable pump works, the high-pressure oil it outputs flows to the first oil inlet 41 and the second oil inlet 42. The oil in the first oil inlet 41 flows to the first damper oil port docking interface 48 and the second damper oil port docking interface 49, and the oil in the second oil inlet 42 flows to the second control oil port 44 and the second spool oil port docking interface 47.

[0054] When the oil in the first oil inlet 41 flows to the first damper oil port docking interface 48 and the second damper oil port docking interface 49, the oil flows into the spool 11 through the first damper oil port 148 and the second damper oil port 149. Since the areas of the first force-receiving surface 111 and the second force-receiving surface 112 of the spool 11 are different, a pressure difference is generated.

[0055] When the pressure difference on both sides of the spool 11 is not enough to push the combined elastic force of the large spring 14 and the small spring 13, the first spool oil port docking interface 46 and the second spool oil port docking interface 47 are disconnected, and the oil flowing into the second oil inlet 42 directly flows into the second control oil port 44, thereby changing the pump displacement.

[0056] When the flow pressure discharged by the variable pump increases, resulting in the pressure difference on both sides of the spool 11 exceeding the combined elastic force of the large spring 14 and the small spring 13, the spool 11 starts to move, and the first spool oil port docking interface 46 and the second spool oil port docking interface 47 are connected. At this time, the oil in the first oil inlet 41 flows into the first control oil port 43 and the second control oil port 44. Although the oil pressures of the first control oil port 43 and the second control oil port 44 are the same, the acting areas are different. Therefore, it will still push the swash plate in the variable pump, thereby changing the pump flow.

[0057] If it is necessary to modify the opening pressure of the spool 11, rotate the adjusting rod 7 to push the adjusting plate 15, and the spring forces of the large spring 14 and the small spring 13 can be modified.

Claims

1. A variable pump flow control device, including a flow control valve, characterized in that: The flow control valve is positioned and connected to the variable pump through a transition plate (4); the flow control valve consists of a valve body (1), a valve sleeve (10) arranged in the inner cavity of the valve body, a valve core (11) matched with the valve sleeve, a protection member (3) matched with the right end of the valve core, and an adjusting rod (7) closely abutted against the left end of the valve core. The protection member (3) is fixedly connected to the right end of the valve body (1) through a right end cover (2), and the adjusting rod (7) is fixedly connected to the left end of the valve body (1) through a left end cover (6); the transition member includes a transition plate (4), the flow control valve is fixed to the transition plate (4) by a plurality of first screws (8), and the transition plate (4) is fixed to the variable pump by a plurality of second screws (9); the flow control valve is provided with an oil return port docking port (145), a first valve core oil port (146), a second valve core oil port (147), a first damping oil port (148) and a second damping oil port (149) communicated with the inner cavity of the valve body, and after being guided by the transition plate (4), it is communicated with the oil inlet and outlet ports of the variable pump.

2. The variable pump flow control device according to claim 1, characterized in that: in A small spring (13) and a large spring (14) are sleeved on the right part of the adjusting rod (7); a baffle (12) is arranged at the right ends of the small spring (13) and the large spring (14), and the baffle is an integral body with the adjusting rod (7) and is closely abutted against the left end of the valve core (11); an adjusting plate (15) is arranged at the left ends of the small spring (13) and the large spring (14), and the adjusting plate is closely abutted against the step on the adjusting rod (7).

3. The variable pump flow control device according to claim 1 or 2, characterized in that: The transition plate (4) of the transition member is provided with a first oil inlet (41), a second oil inlet (42), a first control oil port (43), a second control oil port (44) and an oil return port (45) of the oil return port docking port (145); a first valve core oil port docking port (46) communicated with the first control oil port (43) and a second valve core oil port docking port (47) communicated with the second control oil port (44) are also provided. The first valve core oil port docking port (46) is docked with the first valve core oil port (146), and the second valve core oil port docking port (47) is docked with the second valve core oil port (147); a first damping oil port docking port (48) communicated with the first damping oil port (148) and a second damping oil port docking port (49) communicated with the second damping oil port (149) are also provided.

4. The variable pump flow control device according to claim 1, wherein: The valve sleeve (10) adopts a multi-section groove structure, and oil through holes are added at each section of the groove to ensure that the pressure oil can flow to both sides of the valve core (11).

5. The variable pump flow control device according to claim 1, characterized in that: The valve core (11) is a multi-section variable diameter structure, and the diameters of the left end, the middle part and the right end are equal. The diameters of the connection sections between the left end and the middle part and between the middle part and the right end are equal and smaller than the diameter of the middle part; the right side surface of the middle part of the valve core (11) is a first stress surface (111), and the left end surface is a second stress surface (112).

6. The variable pump flow control device according to claim 1, characterized in that: Both the small spring (13) and the large spring (14) are spiral springs, and the large spring (14) is arranged outside the small spring (13), and their lengths are equal.

7. The variable pump flow control device according to claim 3, wherein: The process holes of the oil channels arranged on the transition plate (4) of the transition member are blocked by first screw plugs (5).

8. The variable pump flow control device according to claim 1, characterized in that: The process holes on the valve body (1) provided with oil passages are all blocked by second screw plugs (18).

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