Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation

Abstract

The utility model discloses a kind of kawasaki hydraulic pump retrofit drive systems based on positive feedback regulation, including swash plate piston pump, servo mechanism for changing its flow is provided on the swash plate piston pump, servo switching valve is connected on the servo mechanism, servo switching valve is connected with pilot piston, proportional solenoid valve is connected on the pilot piston, proportional solenoid valve can switch the connection state of its output port according to the current size input;A kind of kawasaki hydraulic pump retrofit drive systems based on positive feedback regulation of the utility model, can be matched with komatsu computer controller, excavator can work normally.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic control technology, specifically relating to a modified drive system for a Kawasaki hydraulic pump based on positive feedback regulation. Background Technology

[0002] In construction machinery such as hydraulic excavators, hydraulic pumps, typically driven by an engine, supply hydraulic oil to various hydraulic actuators. These actuators are usually controlled based on the actuation position of an operator interface device.

[0003] Komatsu excavators play a vital role in China's infrastructure construction, appearing in cities, subways, and highways. However, when the hydraulic pump of a Komatsu excavator needs replacement, in order to save costs, both domestically and internationally, modified Kawasaki hydraulic pumps are often installed. After the modified Kawasaki hydraulic pump is installed, the quality and workmanship of the regulator feedback device cannot reach the original Komatsu standard. The solenoid valve on the Kawasaki hydraulic pump is incompatible with the Komatsu computer controller, which causes the excavator to sluggish, unable to correctly identify the engine speed, the monitor's working mode, and the operator's operating stroke, resulting in engine overheating, uneven excavator operation, slow movement, and the excavator failing to work normally. Utility Model Content

[0004] The purpose of this invention is to provide a modified drive system for Kawasaki hydraulic pumps based on positive feedback regulation, which solves the problem of mismatch between the solenoid valves of Kawasaki hydraulic pumps and Komatsu computer controllers in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation includes a swashplate piston pump. The swashplate piston pump is equipped with a servo mechanism that changes its flow rate. A servo switching valve is connected to the servo mechanism. The servo switching valve is connected to a pilot piston. An inverse proportional solenoid valve is connected to the pilot piston. The inverse proportional solenoid valve can switch the connection state of its output port according to the magnitude of the input current.

[0007] Optionally, the swashplate piston pump includes a swashplate connected to a servo mechanism, an intake port connected to an oil tank, and a discharge port connected to a hydraulic pump.

[0008] Optionally, the servo mechanism includes a first oil chamber, a servo piston, and a second oil chamber. The first oil chamber is located to the left of the servo piston, and the second oil chamber is located to the right of the servo piston. The servo piston can drive the inclined plate to tilt according to the oil pressure in the first and second oil chambers.

[0009] Optionally, the servo switching valve includes a spool valve and a spool valve sleeve.

[0010] Optionally, the spool sleeve and the servo piston are connected by a connecting rod.

[0011] Optionally, the slide valve sleeve is provided with a first port connected to the first oil chamber, a second port supplied with driving oil, and an oil drain port connected to the oil drain pipe, and the displacement of the slide valve can switch the connection state of the first port, the second port, and the oil drain port.

[0012] Optionally, the inverse proportional solenoid valve has a valve body and a solenoid, and the inverse proportional solenoid valve can drive the valve body to move according to the magnitude of the input current, thereby switching the connection state of the output port.

[0013] Beneficial effects: The Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation of this utility model can be matched with Komatsu computer controller, and the excavator can work normally. Attached Figure Description

[0014] Figure 1 This is an overall control diagram of a Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation, as shown in the embodiment.

[0015] In the diagram: 1. Swashplate piston pump; 11. Swashplate; 12. Suction port; 13. Discharge port; 2. Servo mechanism; 21. First oil chamber; 22. Servo piston; 23. Second oil chamber; 3. Servo switching valve; 31. Spool valve; 32. Spool valve sleeve; 321. First port; 322. Second port; 323. Oil discharge port; 4. Pilot piston; 6. Inverse proportional solenoid valve; 61. Valve body; 62. Solenoid; 601. Output port; 7. Oil tank; 8. Connecting rod. Detailed Implementation

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the present utility model will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is used to help understand this utility model, but does not constitute a limitation on this utility model.

[0017] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0018] In the description of this utility model, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this utility model.

[0019] Example

[0020] like Figure 1 As shown, this embodiment provides a Kawasaki hydraulic pump retrofit control system based on positive feedback regulation, including a swashplate piston pump 1. The swashplate piston pump 1 is equipped with a servo mechanism 2 that changes its flow rate. A servo switching valve 3 is connected to the servo mechanism 2. The servo switching valve 3 is connected to a pilot piston 4. An inverse proportional solenoid valve 6 is connected to the pilot piston 4. The inverse proportional solenoid valve 6 can switch the connection state of its output port 601 according to the magnitude of the input current.

[0021] Specifically, in this embodiment, a K3V112 Kawasaki pump is used for modification. The K3V112 Kawasaki pump adopts a dual pump design and can supply oil to multiple hydraulic systems.

[0022] In this embodiment, two pump units are included, and the two pump units have the same structure. Each pump unit is equipped with a swashplate piston pump 1, a servo mechanism 2, a servo switching valve 3, and a pilot piston 4. The two pump units are controlled by the same inverse proportional solenoid valve 6. The two swashplate piston pumps 1 are connected in series. Of course, there can be three or more swashplate piston pumps 1. Both swashplate piston pumps 1 have a rotating shaft. One rotating shaft is connected to the engine to transmit power from the engine. The other rotating shaft is connected between the two swashplate piston pumps 1 to form a structure in which the two swashplate piston pumps 1 are linked.

[0023] Specifically, the swashplate piston pump 1 includes a swashplate 11 connected to the servo mechanism 2, an intake port 12 connected to the oil tank 7, and an exhaust port 13 connected to the hydraulic pump; working oil is drawn in from the oil tank 7 and supplied to the hydraulic pump.

[0024] The servo mechanism 2 includes a first oil chamber 21, a servo piston 22, and a second oil chamber 23. The first oil chamber 21 is located to the left of the servo piston 22, and the second oil chamber 23 is located to the right of the servo piston 22. The servo piston 22 drives the inclined plate 11 to tilt according to the oil pressure in the first oil chamber 21 and the second oil chamber 23, thereby changing the tilt angle of the inclined plate 11. By means of this, the flow rate of the inclined plate piston pump 1 can be changed.

[0025] The servo switching valve 3 includes a slide valve 31 and a slide valve sleeve 32. The slide valve sleeve 32 is provided with a first port 321 connected to the first oil chamber 21, a second port 322 supplied with driving oil, and an oil drain port 323 connected to the oil drain pipe. The slide valve 31 can reciprocate. Once the slide valve 31 is displaced, it can switch the connection state of the first port 321, the second port 322, and the oil drain port 323. By switching the connection state, the servo piston 22 is made to work, causing the inclined plate 11 to tilt.

[0026] The spool sleeve 32 is connected to the servo piston 22 via a connecting rod 8. The spool sleeve 32 is linked with the servo piston 22 via the connecting rod 8. With the linkage of the spool sleeve 32, the opening degree of the first port 321 and the second port 322 changes. By changing the opening degree, the oil supply state to the first oil chamber 21 of the servo mechanism 2 is switched.

[0027] The pilot piston 4 can withstand the pressure of the pilot oil, and the slide valve 31 is displaced according to the oil pressure; the connection state of the first port 321, the second port 322 and the oil drain port 323 is switched.

[0028] Since the input flow and output flow of the Komatsu original pump have a positive feedback relationship, while the original K3V112 Kawasaki pump has a negative feedback relationship, the original negative feedback control is changed to positive feedback control in this embodiment.

[0029] Specifically, when the input flow at the pilot piston 4 is less than the set value, the pilot piston 4 moves to the right, driving the slide valve 31 to move to the right. When the slide valve 31 moves to the right, the valve core connects to the second port 322, driving oil into the first oil chamber 21. The oil pressure in the first oil chamber 21 is greater than that in the second oil chamber 23. Under the action of the oil pressure, the servo piston 22 is pushed to the right. Under the action of the connecting rod 8, the swashplate 11 rotates clockwise, the opening of the swashplate 11 decreases, and the output flow of the swashplate piston pump 1 decreases, thus realizing positive feedback control.

[0030] When the input flow at the pilot piston 4 is greater than the set value, the pilot piston 4 moves to the left, driving the slide valve 31 to move to the left. When the slide valve 31 moves to the left, the valve core connects to the oil drain port 323, and the driving oil in the first oil chamber 21 is discharged outward. The oil pressure in the first oil chamber 21 is less than that in the second oil chamber 23. Under the action of the oil pressure, the servo piston 22 is pushed to the left. Under the action of the connecting rod 8, the swashplate 11 rotates counterclockwise, the opening of the swashplate 11 increases, and the output flow of the swashplate piston pump 1 increases, thus realizing positive feedback control.

[0031] Since the input current of the Komatsu computer controller is inversely proportional to the output flow of the pump, the original direct proportional solenoid valve must be replaced with an inverse proportional solenoid valve 6 to adapt to the Komatsu computer controller.

[0032] Specifically, in this embodiment, the inverse proportional solenoid valve 6 has a valve body 61 and a solenoid 62. The inverse proportional solenoid valve 6 can drive the valve body 61 to move according to the magnitude of the input current, and switch the connection state of the output port 601. Specifically, the valve body 61 can input an electrical signal, and the solenoid 62 can drive the valve body 61 to move according to the input electrical signal, and switch the connection state with the output port 601.

[0033] When the output current of the computer controller is at its maximum, the input current of the inverse proportional solenoid valve 6 is also at its maximum. The valve body 61 of the inverse proportional solenoid valve 6 moves, the output port 601 is not connected, there is no oil pressure in the oil circuit between the pilot piston 4 and the inverse proportional solenoid valve 6, the pilot piston 4 moves to the right, driving the slide valve 31 to move to the right. When the slide valve 31 moves to the right, the valve core connects to the second port 322, driving oil into the first oil chamber 21. The oil pressure in the first oil chamber 21 is greater than that in the second oil chamber 23. Under the action of the oil pressure, the servo piston 22 is pushed to the right. Under the action of the connecting rod 8, the swashplate 11 rotates clockwise, the opening of the swashplate 11 decreases, and the output flow of the swashplate piston pump 1 decreases.

[0034] When the output current of the computer controller is at its minimum, the input current of the inverse proportional solenoid valve 6 is also at its minimum. The valve body 61 of the inverse proportional solenoid valve 6 moves, the output port 601 is connected, and there is oil pressure in the oil circuit between the pilot piston 4 and the inverse proportional solenoid valve 6. The pilot piston 4 moves to the left, driving the slide valve 31 to move to the left. The slide valve 31 moves to the left, and the valve core is connected to the drain port 323. The driving oil in the first oil chamber 21 is discharged outward. The oil pressure in the first oil chamber 21 is less than that in the second oil chamber 23. Under the action of the oil pressure, the servo piston 22 is pushed to the left. Under the action of the connecting rod 8, the swashplate 11 rotates counterclockwise, the opening of the swashplate 11 increases, and the output flow of the swashplate piston pump 1 increases.

[0035] This invention relates to a Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation, which can be matched with a Komatsu computer controller, enabling the excavator to operate normally.

[0036] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation, characterized in that, The system includes a swashplate piston pump (1), which is connected to a servo mechanism (2) for changing its flow rate. The servo mechanism (2) is connected to a servo switching valve (3), which is connected to a pilot piston (4). The pilot piston (4) is connected to an inverse proportional solenoid valve (6), which can switch the connection state of its output port (601) according to the magnitude of the input current.

2. The Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation according to claim 1, characterized in that, The swashplate piston pump (1) includes a swashplate (11) connected to a servo mechanism (2), an intake port (12) connected to an oil tank (7), and an exhaust port (13) connected to a hydraulic pump.

3. The Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation according to claim 1, characterized in that, The servo mechanism (2) includes a first oil chamber (21), a servo piston (22), and a second oil chamber (23). The first oil chamber (21) is located to the left of the servo piston (22), and the second oil chamber (23) is located to the right of the servo piston (22). The servo piston (22) can drive the inclined plate (11) to tilt according to the oil pressure in the first oil chamber (21) and the second oil chamber (23).

4. The Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation according to claim 3, characterized in that, The servo switching valve (3) includes a slide valve (31) and a slide valve sleeve (32).

5. A Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation according to claim 4, characterized in that, The spool sleeve (32) is connected to the servo piston (22) via a connecting rod (8).

6. The Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation according to claim 4, characterized in that, The slide valve sleeve (32) is provided with a first port (321) connected to the first oil chamber (21), a second port (322) supplied with driving oil, and an oil drain port (323) connected to the oil drain pipe. The displacement of the slide valve (31) can switch the connection state of the first port (321), the second port (322) and the oil drain port (323).

7. A Kawasaki hydraulic pump retrofit drive system based on positive feedback regulation according to claim 1, characterized in that, The inverse proportional solenoid valve (6) has a valve body (61) and a solenoid (62). The inverse proportional solenoid valve (6) can drive the valve body (61) to move according to the magnitude of the input current and switch the connection state of the output port (601).

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