Plunger variable pump and hydraulic system

Abstract

The utility model discloses a plunger variable pump and a hydraulic system, the plunger variable pump comprises a pump body, the pump body comprises a base pump, a variable cylinder and a mode switching control valve, a piston rod is arranged in the variable cylinder, and an inner cavity of the variable cylinder is divided into a motor cavity and a pump cavity by the piston rod; the base pump is respectively communicated with a first oil port end and a second oil port end of the pump body and the motor cavity through pipelines; the mode switching control valve is respectively communicated with the pilot oil port end of the pump body, the motor cavity and the pump cavity, is electrically connected with an external control module, and is used for switching and controlling pilot oil to enter the motor cavity or the pump cavity according to an externally input mode control signal; and the piston rod moves back and forth in the variable cylinder. The energy circulation function of the hydraulic system can be achieved, the overall structure is simple, and cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic systems, in particular to a plunger variable displacement pump and a hydraulic system. Background Art

[0002] Current energy-circulating hydraulic systems incorporate pumps and motors to achieve both energy output and energy recovery. These systems consist of a basic pump mechanism and a motor mechanism, with the basic pump mechanism achieving energy output and the motor mechanism achieving energy recovery. However, the addition of motors and generators to hydraulic systems leads to complex overall structures, large space requirements, and high equipment costs. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a plunger variable pump and a hydraulic system, which can realize the energy circulation function of the hydraulic system, have a simple overall structure and low cost.

[0004] In order to solve the above technical problems, the utility model provides a plunger variable pump, including a pump body, the pump body including a base pump, a variable cylinder and a mode switching control valve, a piston rod is provided in the variable cylinder, and the piston rod divides the inner cavity of the variable cylinder into a motor cavity and a pump cavity; the base pump is connected to the first oil port end, the second oil port end and the motor cavity of the pump body through pipelines respectively; the mode switching control valve is connected to the pilot oil port end of the pump body, the motor cavity and the pump cavity respectively, and the mode switching control valve is electrically connected to an external control module, and is used for switching and controlling the pilot oil to enter the motor cavity or the pump cavity according to a mode control signal input from the outside, so that the piston rod moves back and forth in the variable cylinder.

[0005] As an improvement to the above solution, a connecting rod is provided at one end of the piston rod away from the motor chamber, and the connecting rod is connected to the displacement detection device; the displacement detection device is electrically connected to the external control module for detecting the displacement of the piston rod and sending it to the external control module.

[0006] As an improvement of the above-mentioned scheme, the mode switching control valve includes a valve body, which includes a first solenoid valve and a second solenoid valve electrically connected to the external control module, and the oil inlet end of the valve body is connected to the pilot oil port end; the valve port of the first solenoid valve is respectively connected to the oil inlet end and the motor cavity, and the valve port of the second solenoid valve is respectively connected to the oil inlet end and the pump cavity.

[0007] As an improvement of the above solution, the piston rod includes a piston head and a piston connecting rod, the piston connecting rod is provided at one end of the piston head close to the motor chamber, and the connecting rod is provided at one end of the piston head close to the pump chamber.

[0008] As an improvement to the above-mentioned scheme, a first spring portion is provided in the motor chamber, the first spring portion is sleeved on the piston connecting rod, one end of the first spring portion is in contact with the piston head, and the other end of the first spring portion is in contact with an inner wall of one side of the motor chamber; a second spring portion is provided in the pump chamber, the second spring portion is sleeved on the connecting rod, one end of the second spring portion is in contact with the piston head, and the other end of the second spring portion is in contact with an inner wall of one side of the pump chamber.

[0009] As an improvement to the above solution, the base pump is connected to the variable cylinder via a drive shaft to drive the variable cylinder to rotate.

[0010] As an improvement to the above solution, the displacement detection device is a linear displacement sensor.

[0011] As an improvement to the above solution, the mode switching control valve is a three-position four-way electromagnetic control valve.

[0012] As an improvement to the above solution, the displacement detection device is arranged on the outer wall of the pump body.

[0013] The utility model also provides a hydraulic system, which includes the above-mentioned plunger variable pump.

[0014] The implementation of this utility model has the following beneficial effects:

[0015] This utility model controls the flow of pilot oil into the pump chamber via a mode switching control valve, pushing the piston rod in the hydraulic cylinder toward the motor chamber, causing the base pump to operate at maximum displacement. The variable cylinder rotates +15° to achieve energy output. The mode switching control valve also controls the flow of pilot oil into the motor chamber, pushing the piston rod toward the pump chamber, causing the base pump to operate at maximum displacement. The variable cylinder rotates -15° to achieve energy recovery. Therefore, this utility model achieves energy recycling without the need for additional equipment such as a motor and generator, resulting in a simple overall structure, small footprint, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the logic control structure of the utility model plunger variable pump;

[0017] Figure 2 It is a structural diagram of the utility model plunger variable pump. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that any directional terms such as "up," "down," "left," "right," "front," "back," "inside," and "outside" that appear or will appear in this document are based solely on the accompanying drawings and are not intended to limit the present invention.

[0019] like Figures 1 to 2 As shown, a specific embodiment of the present invention provides a plunger variable pump, including a pump body 1, wherein the pump body 1 includes a base pump 2, a variable cylinder 3 and a mode switching control valve 4, a piston rod 31 is provided in the variable cylinder 3, and the piston rod 31 divides the inner cavity of the variable cylinder 3 into a motor cavity 32 and a pump cavity 33; the base pump 2 is connected to the first oil port end, the second oil port end and the motor cavity 32 of the pump body 1 through pipelines respectively; the mode switching control valve 4 is connected to the pilot oil port end (P) of the pump body 1, the motor cavity 32 and the pump cavity 33 respectively, and the mode switching control valve 4 is electrically connected to an external control module, and is used for switching and controlling the pilot oil to enter the motor cavity 32 or the pump cavity 33 according to a mode control signal input from the outside, so that the piston rod 31 moves back and forth in the variable cylinder 3.

[0020] It should be noted that when flow activation (i.e., energy output) is required, a first mode control signal is output to the mode switching control valve 4 through the external control module, causing the mode switching control valve 4 to control the pilot oil port to communicate with the pump chamber 33. Pilot oil, or hydraulic oil, flowing into the pump chamber 33 pushes the piston rod 31 toward the motor chamber 32. At this time, the base pump 2 operates at maximum displacement, driving the rotating shaft 21 to rotate the variable cylinder 3 by +15°, i.e., the plunger variable pump is performing its pumping function. When performing the pumping function, external hydraulic oil enters the base pump 2 from the first oil port (S) and, after being pressurized, flows out from the second oil port (B).

[0021] When unloading flow is required to start (i.e., energy recovery), the second mode control signal is output to the mode switching control valve 4 through the external control module, so that the mode switching control valve 4 controls the pilot oil port end to be connected with the motor cavity 32. The pilot oil flowing into the motor cavity 32 can push the piston rod 31 to move in the direction of the pump cavity 33. At this time, the base pump 2 works in the maximum displacement condition. The base pump 2 will drive the rotating shaft 21 to drive the variable cylinder 3 to rotate in the opposite direction by -15°, that is, the plunger variable pump is performing the motor function. When performing the motor function, the external hydraulic oil enters the base pump 2 from the second oil port end (B) and flows out from the first oil port end (S) after energy conversion. In the above manner, the utility model can realize the energy circulation function without adding equipment such as motors and generators. The overall structure is simple, the space occupied is small, and the cost is low.

[0022] In order to facilitate the monitoring of the rotation angle of the variable cylinder 3. Figure 1 As shown, a connecting rod 34 is provided at the end of the piston rod 31 away from the motor chamber 32. This connecting rod 34 is connected to the displacement detection device 5. The displacement detection device 5 is electrically connected to the external control module and is used to detect the displacement of the piston rod 31 and transmit it to the external control module. When the piston variable pump is operating as a pump, the piston rod 31 moves toward the motor chamber 32, driving the connecting rod 34 to move synchronously, thereby pulling the displacement detection device 5. The displacement of the piston rod 31 is detected based on this pulling force. The displacement detection device 5 provides feedback of a corresponding voltage signal to the external control module, which converts the voltage signal into an angle to detect the angle in the forward direction of the variable cylinder 3. When the piston variable pump is operating as a motor, the piston rod 31 moves toward the pump chamber 33, driving the connecting rod 34 to move synchronously, thereby compressing the displacement detection device 5. The displacement of the piston rod 31 is detected based on this compression force. The displacement detection device 5 provides feedback of a corresponding voltage signal to the external control module, which converts the voltage signal into an angle to detect the angle in the reverse direction of the variable cylinder 3.

[0023] The displacement detection device 5 is a linear displacement sensor, and the voltage range of its detection feedback is 2.5±2.5V. This voltage range corresponds to a rotation angle of ±15° for the variable cylinder 3. For example, when the variable cylinder 3 rotates positively at a +15° angle, the feedback voltage is (2.5+2.5)V. Conversely, when the variable cylinder 3 rotates negatively at a -15° angle, the feedback voltage is (2.5-2.5)V.

[0024] Furthermore, if Figures 1 to 2 As shown, the mode switching control valve 4 includes a valve body 41, which includes a first solenoid valve 42 and a second solenoid valve 43 electrically connected to the external control module. The oil inlet end 411 of the valve body 41 is connected to the pilot oil port. The valve port of the first solenoid valve 42 communicates with the oil inlet end 411 and the motor chamber 32, respectively, while the valve port of the second solenoid valve 43 communicates with the oil inlet end 411 and the pump chamber 33, respectively. When flow activation is required, a first preset current is output to the second solenoid valve 43 via the external control module, connecting the pilot oil port with the pump chamber 33. Pilot oil flows into the pump chamber 33, pushing the piston rod 31 toward the motor chamber 32. At this point, the base pump 2 operates at maximum displacement, driving the rotating shaft 21 to rotate the variable cylinder 3 by +15°, effectively performing the plunger variable pump function. When performing the pump function, external hydraulic oil enters the base pump 2 from the first oil port (S) and flows out from the second oil port (B) after being pressurized; the displacement of the base pump 2 is proportional to the first preset current. For example, when the first preset current is 200-600mA, the corresponding displacement state of the base pump 2 is 0-100%.

[0025] When unloading flow is required, a second preset current is output to the first solenoid valve 42 via the external control module, controlling the communication between the pilot oil port and the motor chamber 32. Pilot oil flowing into the motor chamber 32 pushes the piston rod 31 toward the pump chamber 33. At this point, the base pump 2 operates at maximum displacement, driving the rotating shaft 21 to rotate the variable in the opposite direction by -15°, effectively acting as a motor. When operating as a motor, external hydraulic oil enters the base pump 2 through the second port (B) and, after energy conversion, flows out of the first port (S). The displacement of the base pump 2 is proportional to the second preset current. For example, when the second preset current is between 200-600 mA, the corresponding displacement state of the base pump 2 is between 0-100%.

[0026] Preferably, if Figure 1 As shown, the piston rod 31 includes a piston head 35 and a piston connecting rod 36 . The piston connecting rod 36 is provided at one end of the piston head 35 close to the motor chamber 32 , and the connecting rod 34 is provided at one end of the piston head 35 close to the pump chamber 33 .

[0027] The motor chamber 32 is provided with a first spring portion 37, which is sleeved on the piston connecting rod 36. One end of the first spring portion 37 abuts the piston head 35, and the other end abuts the inner wall of one side of the motor chamber 32. The pump chamber 33 is provided with a second spring portion 38, which is sleeved on the connecting rod 34. One end of the second spring portion 38 abuts the piston head 35, and the other end abuts the inner wall of one side of the pump chamber 33. The provision of the first spring portion 37 and the second spring portion 38 prevents the piston head 35 from excessively moving and damaging the variable cylinder, and also assists in providing the moving power of the piston rod 31.

[0028] Preferably, the mode switching control valve 4 is a three-position four-way electromagnetic control valve, but is not limited thereto.

[0029] Preferably, if Figure 2 As shown, the displacement detection device 5 is arranged on the outer wall of the pump body 1.

[0030] Preferably, the present invention further provides a hydraulic system comprising the above-mentioned plunger variable pump. Since the above-mentioned plunger variable pump has the above-mentioned technical effects, the hydraulic system comprising the above-mentioned plunger variable pump should also have the above-mentioned technical effects, which will not be described in detail here.

[0031] In summary, the present invention can control the flow of pilot oil into the pump chamber 33 through the mode switching control valve 4, thereby pushing the piston rod 31 in the hydraulic cylinder toward the motor chamber 32, causing the base pump 2 to operate at maximum displacement and the variable cylinder 3 to rotate +15°, achieving energy output. The mode switching control valve 4 can also switch the flow of pilot oil into the motor chamber 32, thereby pushing the piston rod 31 toward the pump chamber 33, causing the base pump 2 to operate at maximum displacement and the variable cylinder 3 to rotate -15°, achieving energy recovery. Therefore, the present invention can achieve energy recycling without the need for additional equipment such as motors and generators, resulting in a simple overall structure, small footprint, and low cost.

[0032] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.

Claims

1. A plunger variable pump, characterized in that: The pump body includes a base pump, a variable cylinder and a mode switching control valve. A piston rod is provided in the variable cylinder, and the piston rod divides the inner cavity of the variable cylinder into a motor cavity and a pump cavity. The base pump is connected to the first oil port end, the second oil port end and the motor cavity of the pump body through pipelines respectively; The mode switching control valve is respectively connected to the pilot oil port end of the pump body, the motor chamber and the pump chamber. The mode switching control valve is electrically connected to the external control module and is used to switch and control the pilot oil into the motor chamber or the pump chamber according to the external input mode control signal, so that the piston rod moves back and forth in the variable cylinder.

2. The variable displacement piston pump according to claim 1, characterized in that: A connecting rod is provided at one end of the piston rod away from the motor chamber, and the connecting rod is connected to the displacement detection device; The displacement detection device is electrically connected to the external control module and is used to detect the displacement of the piston rod and send the displacement to the external control module.

3. The variable displacement piston pump according to claim 2, characterized in that: The mode switching control valve includes a valve body, the valve body includes a first solenoid valve and a second solenoid valve electrically connected to the external control module, and the oil inlet end of the valve body is connected to the pilot oil port end; The valve port of the first solenoid valve is communicated with the oil inlet end and the motor chamber respectively, and the valve port of the second solenoid valve is communicated with the oil inlet end and the pump chamber respectively.

4. The variable displacement piston pump according to claim 2, characterized in that: The piston rod includes a piston head and a piston connecting rod. The piston connecting rod is provided at one end of the piston head close to the motor chamber, and the connecting rod is provided at one end of the piston head close to the pump chamber.

5. The variable displacement piston pump according to claim 4, characterized in that: A first spring portion is provided in the motor cavity, the first spring portion is sleeved on the piston connecting rod, one end of the first spring portion abuts against the piston head, and the other end of the first spring portion abuts against an inner wall of one side of the motor cavity; A second spring portion is provided in the pump chamber. The second spring portion is sleeved on the connecting rod. One end of the second spring portion abuts against the piston head, and the other end of the second spring portion abuts against an inner wall of one side of the pump chamber.

6. The variable displacement piston pump according to claim 1, characterized in that: The base pump is connected to the variable cylinder via a driving shaft, and is used to drive the variable cylinder to rotate.

7. The variable displacement piston pump according to claim 2, characterized in that: The displacement detection device is a linear displacement sensor.

8. The variable displacement piston pump according to claim 3, characterized in that: The mode switching control valve is a three-position four-way electromagnetic control valve.

9. The variable displacement piston pump according to claim 2, characterized in that: The displacement detection device is arranged on the outer wall of the pump body.

10. A hydraulic system, characterized in that: The hydraulic system includes the plunger variable displacement pump according to any one of claims 1 to 9.

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