Variable displacement piston pump with compound control function

Abstract

The utility model discloses a variable displacement piston pump with a compound control function, a control valve and an oil supplementing pump (8) are integrated on the variable displacement piston pump, a driving electromagnetic valve mechanism (3) is integrated on the control valve, the oil supplementing pump (8) is connected with a variable displacement cavity in the variable displacement piston pump through the driving electromagnetic valve mechanism (3), a switch valve mechanism (7) is arranged on a rear cover (20) of the variable displacement piston pump, and the switch valve mechanism (7) is connected with the control valve. A branch oil way is arranged in a rear cover (20) of the variable displacement piston pump, the branch oil way is provided with an oil inlet end and two oil outlet ends, the oil inlet end of the branch oil way is connected with an oil supplementing pump (8), the two oil outlet ends of the branch oil way are connected with an active electromagnetic valve mechanism (3) and a switch valve mechanism (7) respectively, and the switch valve mechanism (7) is connected with a shell cavity of the variable displacement piston pump. The utility model has the advantage of high safety.

Description

Technical Field

[0001] The utility model belongs to the field of variable plunger pumps, in particular to a variable plunger pump with a compound control function. Background Art

[0002] As the heart of mechanical products, variable displacement piston pumps are usually used as energy pumps for many high-pressure and heavy-load actuators. They are responsible for high-load and high-risk operations such as product rotation and lifting. Therefore, their working safety and controllability in emergency situations are particularly important.

[0003] The existing variable plunger pump is integrated with a control valve and a replenishing pump. The control valve is integrated with an active solenoid valve mechanism. The replenishing pump provides pilot oil, which is sent to the variable cavity inside the variable plunger pump under the control of the active solenoid valve mechanism. The active solenoid valve mechanism controls the pressure by connecting the two sides of the variable cavity inside the variable plunger pump, so that the pressure on both sides of the variable cylinder is equal, and no tilting force is provided to the swash plate. The swash plate automatically recovers and remains horizontal due to the elastic force of the return spring inside the variable plunger pump, and returns to the middle position, so that the variable plunger pump has no output, thereby achieving braking of the actuator. However, since there is still high-pressure pilot oil on both sides of the variable cavity, the swash plate returns to the middle position slowly, resulting in the variable plunger pump still being in the output state, and the actuator cannot brake in time, and the safety is poor. Utility Model Content

[0004] The purpose of the utility model is to provide a variable displacement plunger pump with a compound control function. The utility model has the advantage of high safety.

[0005] The technical solution of the utility model: a variable piston pump with a compound control function, the variable piston pump is integrated with a control valve and an oil replenishment pump, the control valve is integrated with an active solenoid valve mechanism, the oil replenishment pump is connected to a variable cavity inside the variable piston pump via the active solenoid valve mechanism, a switch valve mechanism is provided on the rear cover of the variable piston pump, a branch oil circuit is provided in the rear cover of the variable piston pump, the branch oil circuit has an oil inlet end and two oil outlet ends, the oil inlet end of the branch oil circuit is connected to the oil replenishment pump, the two oil outlet ends of the branch oil circuit are respectively connected to the active solenoid valve mechanism and the switch valve mechanism, and the switch valve mechanism is connected to the shell cavity of the variable piston pump.

[0006] In the aforementioned variable plunger pump with compound control function, the switch valve mechanism includes a valve sleeve plugged into the rear cover, one end of the valve sleeve is provided with a switch electromagnet, the other end of the valve sleeve is provided with a plug, the inner side of the plug forms a first oil chamber, the plug is axially provided with a first oil hole, the inner end of the first oil hole is connected to the first oil chamber, the outer end of the first oil hole is connected to the housing chamber of the variable plunger pump, a valve core is provided in the valve sleeve, an annular groove is provided on the valve core, one end of the valve core is connected to the control end of the switch electromagnet, a second oil hole is radially provided with the valve sleeve, the inner end of the second oil hole is connected to the annular groove, and the outer end of the second oil hole is connected to the branch oil circuit.

[0007] In the aforementioned variable piston pump with compound control function, a spring chamber is formed between the valve sleeve and the switch electromagnet, a spring is arranged in the spring chamber, and a retaining ring connected to the valve core is arranged on the side of the spring close to the switch electromagnet.

[0008] In the aforementioned variable displacement plunger pump with compound control function, a spring seat is provided between the retaining ring and the spring.

[0009] In the aforementioned variable piston pump with compound control function, a blind hole is provided on the rear cover, a screw plug is provided at the end of the blind hole, a one-way valve is provided on the inner side of the screw plug, and a second oil chamber is formed between the screw plug and the one-way valve, the second oil chamber is connected to the oil replenishment pump, and the second oil chamber is connected to the second oil hole through the one-way valve.

[0010] In the aforementioned variable plunger pump with compound control function, the pilot oil outputted by the oil replenishment pump is all allowed to enter the variable cavity inside the variable plunger pump through the active solenoid valve mechanism through the switch valve mechanism, thereby controlling the variable output of the variable plunger pump;

[0011] The pilot oil output by the oil replenishment pump enters the housing cavity of the variable piston pump through the switch valve mechanism, thereby achieving timely braking of the actuator connected to the variable piston pump.

[0012] Compared with the prior art, the utility model opens a branch oil circuit on the rear cover on the basis of the existing variable plunger pump, the oil inlet end of the branch oil circuit is connected to the oil replenishment pump, one of the oil outlet ends of the branch oil circuit is connected to the active solenoid valve mechanism, and the other oil outlet end of the branch oil circuit is connected to the housing cavity of the variable plunger pump through the switch valve mechanism. When the switch valve mechanism is disconnected, the pilot oil output by the oil replenishment pump all enters the active solenoid valve mechanism, enters the variable cavity through the control of the active solenoid valve mechanism, and maintains the normal variable output of the variable plunger pump. When the switch valve mechanism is connected, the pilot oil output by the oil replenishment pump enters the housing cavity of the plunger pump and can return to the oil tank, so that the active solenoid valve mechanism has no pilot oil entering, the pressure in the variable cavity quickly returns to zero, the swash plate can quickly return to the middle position, and there is no flow output, so as to achieve rapid braking of the actuator. The utility model cuts off the input of the pilot oil in the variable cavity from the root, so that the swash plate can return to the middle position in a timely, effective and reliable manner, and the variable plunger pump has no output, so that the braking effect of the actuator is good and the safety is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] Figure 2 It is a structural diagram of the back cover.

[0015] Figure 3 It is a structural schematic diagram of the switch valve mechanism.

[0016] Figure 4 It is the hydraulic principle diagram of Example 2.

[0017] The marks in the accompanying drawings are: 2-variable cylinder, 3-active solenoid valve mechanism, 4-first high-pressure relief valve, 5-screw plug, 6-check valve, 7-switch valve mechanism, 8-oil replenishment pump, 9-pressure cut-off valve, 10-low-pressure relief valve, 11-second high-pressure relief valve, 12-spindle assembly, 13-housing assembly, 14-ball joint plunger assembly, 15-swash plate;

[0018] 20-rear cover, 200-second oil chamber;

[0019] 700-valve sleeve, 701-switch solenoid, 702-plug, 703-first oil chamber, 704-first oil hole, 705-valve core, 706-annular groove, 707-second oil hole, 708-spring chamber, 709-spring, 710-retaining ring, 711-spring seat. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0021] Embodiment 1. A variable displacement piston pump with a compound control function includes existing components such as a main shaft assembly 12, a housing assembly 13, a ball joint piston assembly 14, a swash plate 15, and a variable displacement cylinder 2. A control valve and a replenishing oil pump 8 are integrated on the outside of the variable displacement piston pump. An active solenoid valve mechanism 3 is integrated on the control valve. The active solenoid valve mechanism 3 is a proportional solenoid valve. The replenishing oil pump 8 is connected to a variable cavity (formed in the variable displacement cylinder 2) inside the variable displacement piston pump via the active solenoid valve mechanism 3. The features are as follows:

[0022] like Figure 1 As shown, a switch valve mechanism 7 is provided on the rear cover 20 of the variable piston pump, and a branch oil circuit is provided inside the rear cover 20 of the variable piston pump. The branch oil circuit has an oil inlet end and two oil outlet ends. The oil inlet end of the branch oil circuit is connected to the oil replenishment pump 8, and the two oil outlet ends of the branch oil circuit are respectively connected to the active solenoid valve mechanism 3 and the switch valve mechanism 7, and the switch valve mechanism 7 is connected to the shell cavity of the variable piston pump.

[0023] The switch valve mechanism 7 includes a valve sleeve 700 inserted into the rear cover 20, one end of the valve sleeve 700 is provided with a switch electromagnet 701, the other end of the valve sleeve 700 is provided with a plug 702, the inner side of the plug 702 forms a first oil chamber 703, the first oil chamber 703 can be provided with a filter screen fixed to the plug 702 for filtering oil impurities, the plug 702 is axially provided with a first oil hole 704, the inner side end of the first oil hole 704 is connected to the first oil chamber 703, the outer side end of the first oil hole 704 is connected to the housing cavity of the variable plunger pump, a valve core 705 is provided in the valve sleeve 700, the valve core 705 is provided with an annular groove 706, one end of the valve core 705 is connected to the control end of the switch electromagnet 701, and a second oil hole 707 is radially provided on the valve sleeve 700, the inner side end of the second oil hole 707 is connected to the annular groove 706, and the outer side end of the second oil hole 707 is connected to the oil outlet end of the one-way valve 6. A spring cavity 708 is formed between the valve sleeve 700 and the switch electromagnet 701 , in which a spring 709 is arranged. A retaining ring 710 connected to the valve core 705 is arranged on the side of the spring 709 close to the switch electromagnet 701 , and a spring seat 711 is arranged between the retaining ring 710 and the spring 709 .

[0024] The rear cover 20 is provided with a blind hole, a screw plug 5 is provided at the end of the blind hole, a one-way valve 6 is provided inside the screw plug 5 , a second oil chamber 200 is formed between the screw plug 5 and the one-way valve 6 , and the second oil chamber 200 is connected to the oil replenishment pump 8 .

[0025] The branch oil circuit is composed of three parts. The first part is formed in the oil circuit between the oil replenishing pump 8 and the second oil chamber 200 , the second part is formed in the oil circuit between the active solenoid valve mechanism 3 and the second oil chamber 200 , and the third part is formed in the oil circuit between the second oil chamber 200 and the second oil hole 707 .

[0026] Working principle: The pilot oil output by the oil replenishment pump 8 has two output directions after entering the second oil chamber 200. The first output direction is to enter the variable chamber of the variable cylinder 2 through the active solenoid valve mechanism 3, and the second output direction is to enter the shell chamber through the switch valve mechanism 7 and then return to the oil tank.

[0027] Instructions for use, working condition 1: Figure 2 As shown, the switch electromagnet 701 is energized, and the control end of the electromagnet 701 moves to the left, driving the valve core 705 to move to the left to overcome the preload of the spring 709. At this time, the annular groove 706 is not connected to the first oil chamber 703, and the second output direction is cut off. The pilot oil cannot pass through the switch valve mechanism 7, but all enters the active electromagnetic valve mechanism 3, and is regulated by the active electromagnetic valve mechanism 3 to flow into the corresponding variable chamber of the variable cylinder 2, so that the variable piston pump maintains normal variable output. The control principle of the working condition 1 is the same as that of the existing variable piston pump.

[0028] Working condition 2: When the actuator connected to the variable piston pump needs to brake, such as when the construction machinery stops moving, the switch electromagnet 701 is powered off, and under the elastic force of the spring 709, the valve core 705 moves right, and the annular groove 706 is connected with the first oil chamber 703. After the pilot oil output by the replenishing pump 8 enters the second oil chamber 200, it returns to the housing chamber of the variable piston pump through the one-way valve 6, the second oil hole 707, the annular groove 706, the first oil chamber 703, the first oil hole 704, and the T port, and then returns to the oil tank. Due to the characteristics of hydraulic pressure, no high-pressure pilot oil enters the variable chamber of the variable cylinder 2. After the active solenoid valve mechanism 3 connects the two sides of the variable chamber, the oil in the variable chamber is low-pressure, the swash plate quickly and automatically returns to the middle position, the variable piston pump has no flow output, and the actuator achieves automatic braking.

[0029] Example 2. Figure 3 As shown, on the basis of Example 1, the first high-pressure relief valve 4, the pressure cut-off valve 9, the low-pressure relief valve 10, the second high-pressure relief valve 11 and other components are also integrated, and the low-pressure relief valve 10 can control the pressure value of the pilot oil.

Claims

1. A variable displacement piston pump with a composite control function, wherein a control valve and a replenishing oil pump (8) are integrated on the variable displacement piston pump, an active electromagnetic valve mechanism (3) is integrated on the control valve, and the replenishing oil pump (8) is connected to a variable cavity inside the variable displacement piston pump via the active electromagnetic valve mechanism (3), characterized in that: A switch valve mechanism (7) is provided on the rear cover (20) of the variable piston pump, and a branch oil circuit is provided inside the rear cover (20) of the variable piston pump. The branch oil circuit has an oil inlet end and two oil outlet ends. The oil inlet end of the branch oil circuit is connected to the oil replenishment pump (8), and the two oil outlet ends of the branch oil circuit are respectively connected to the active solenoid valve mechanism (3) and the switch valve mechanism (7), and the switch valve mechanism (7) is connected to the housing cavity of the variable piston pump.

2. The variable displacement plunger pump with compound control function according to claim 1, characterized in that: The switch valve mechanism (7) comprises a valve sleeve (700) inserted into the rear cover (20), one end of the valve sleeve (700) is provided with a switch electromagnet (701), the other end of the valve sleeve (700) is provided with a plug (702), the inner side of the plug (702) forms a first oil chamber (703), the plug (702) is axially provided with a first oil hole (704), the inner side end of the first oil hole (704) is connected to the first oil chamber (703), and the first oil hole (704) is connected to the first oil chamber (703). The outer end of the valve sleeve (704) is connected to the housing cavity of the variable piston pump, a valve core (705) is provided in the valve sleeve (700), an annular groove (706) is provided on the valve core (705), one end of the valve core (705) is connected to the control end of the switch electromagnet (701), and a second oil hole (707) is provided in the radial direction of the valve sleeve (700), the inner end of the second oil hole (707) is connected to the annular groove (706), and the outer end of the second oil hole (707) is connected to the branch oil circuit.

3. The variable displacement plunger pump with compound control function according to claim 2, characterized in that: A spring chamber (708) is formed between the valve sleeve (700) and the switch electromagnet (701), a spring (709) is arranged in the spring chamber (708), and a retaining ring (710) connected to the valve core (705) is arranged on the side of the spring (709) close to the switch electromagnet (701).

4. The variable displacement plunger pump with compound control function according to claim 3, characterized in that: A spring seat (711) is provided between the retaining ring (710) and the spring (709).

5. The variable displacement plunger pump with compound control function according to claim 2, characterized in that: The rear cover (20) is provided with a blind hole, a screw plug (5) is provided at the end of the blind hole, a one-way valve (6) is provided on the inner side of the screw plug (5), a second oil chamber (200) is formed between the screw plug (5) and the one-way valve (6), the second oil chamber (200) is connected to the oil replenishment pump (8), and the second oil chamber (200) is connected to the second oil hole (707) through the one-way valve (6).

6. The variable displacement plunger pump with compound control function according to claim 1, characterized in that: The active solenoid valve mechanism (3) is a proportional solenoid valve.

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