CN104806406A - Normally closed electromechanical compound high pressure oil pump - Google Patents

Abstract

The invention aims to provide a normally closed electromechanical composite high-pressure oil pump which comprises a roller plunger, a normally closed fuel control valve and an oil outlet valve. The roller plunger is arranged at the bottom of the pump body and consists of a roller, a plunger spring, a gear ring, a rack bar, an oil inlet hole, an oil return hole and a plunger cavity, wherein the plunger is provided with a spiral groove. The normally closed fuel control valve is installed above the plunger and comprises a solenoid valve, a solenoid valve rod, a solenoid valve spring, an oil drainage cone valve connecting sleeve, an oil drainage cone valve rod and an oil drainage cone valve spring. The normally closed fuel control valve is in a closed state when not electrified, and after electrification, the oil drainage cone valve opens the oil drainage oil way. The invention improves the reliability of engine hydraulic systems such as a high-pressure oil pump, an oil sprayer and the like, and improves the stability of the operation of the engine. The size and the form of the electromagnetic force of the fuel control electromagnetic valve can be changed to realize different fuel supply time, fuel supply time and fuel supply quantity requirements of the engine under different working conditions and different loads.

Description

Normally closed electromechanical compound high pressure oil pump

technical field

The invention relates to a fuel injection device, in particular to an engine fuel injection device.

Background technique

The two serious problems faced by mankind in today's society are energy shortage and environmental pollution. Engines are widely used in domestic industries due to their high power, long life and good power performance. However, the traditional technology engine is gradually eliminated due to its shortcomings of high energy consumption and high emission, and the research on an engine with less energy consumption, high efficiency and good emission performance has become an inevitable trend of engine development. In recent years, the development of electronic control technology has provided technical support for the innovation of engine technology, and the electronic control fuel system of the engine has become the main means to solve engine problems. The electronically controlled high-pressure fuel pump is an important technical means. It is a time-controlled fuel injection system that can meet engine emission regulations and economic requirements. It has the characteristics of high fuel injection pressure and flexible and adjustable fuel injection timing.

The traditional electronically controlled high-pressure fuel pump uses a roller to push the plunger to pressurize the fuel, and a normally open solenoid valve controls the way of fuel drain and fuel supply. The plunger only completes the work of fuel pressurization. When the normally open solenoid valve is not powered on, the oil drain circuit is in the normally open state, and the fuel in the high-pressure fuel pump flows back to the fuel tank through the oil drain circuit; when the solenoid valve is powered on , close the drain oil circuit by electromagnetic force, and the fuel pressurized by the plunger often opens the valve and flows to the injector. However, the common normally open electronically controlled high-pressure oil pump has the following disadvantages: first, when the solenoid valve cannot be powered on due to a fault such as a power failure of the engine, the oil discharge circuit of the high-pressure oil pump is in a normally open state, and the high-pressure oil pump cannot complete the emergency oil supply work; Second, when the solenoid valve is stuck in the closed state, the oil pressure in the valve will continue to rise, causing adverse effects on the solenoid valve and the fuel injector, causing damage to other hydraulic devices such as the fuel injector; When there is any failure but still able to supply oil, the high-pressure oil pump cannot complete the adjustment of the oil supply time and quantity. In short, the traditional electronically controlled high-pressure oil pump has poor safety, does not have the ability to respond to failures in an emergency, and cannot meet the requirements of engine stability and safety.

Contents of the invention

The object of the present invention is to provide a normally closed electromechanical composite high-pressure oil pump for improving engine stability and reliability.

The purpose of the present invention is achieved like this:

The normally closed electromechanical composite high-pressure oil pump of the present invention is characterized in that: it includes a roller plunger, a normally closed fuel control valve, and an oil outlet valve; the roller plunger includes a pump body, a plunger sleeve, a housing, a plunger, and a roller, The plunger sleeve is installed in the casing, and the pump body is set under the casing. The plunger is covered with a plunger spring. The upper part is located in the plunger sleeve, and the lower part is located in the pump body. On the plug sleeve, the lower end of the plunger spring is pushed against the pump body, the inner wall of the housing is provided with a gear rod, the outer wall of the plunger sleeve is provided with a ring gear matching the gear rod, and a plunger cavity is formed between the plunger and the wall of the plunger sleeve at the upper end , the plunger sleeve is provided with an oil inlet hole, an oil return hole and the first oil passage, and the side wall of the upper end of the plunger is provided with a spiral groove for controlling the connection and disconnection between the plunger chamber and the oil return hole; the normally closed fuel control valve includes Control valve body, solenoid valve body, solenoid valve stem, oil drain cone valve, oil drain cone valve stem, the control valve body and solenoid valve body are arranged side by side, and the oil drain cone valve and oil drain cone valve stem are arranged on the control valve In the body, the solenoid valve body is connected to the first end of the oil discharge cone valve through the solenoid valve stem. The second end of the oil discharge cone valve is a conical end face, which cooperates with the control valve body next to it. The oil discharge cone valve The first end of the valve stem is connected to the second end of the oil relief poppet valve, and the second end of the oil relief poppet valve stem is pressed against the spring of the oil relief poppet valve, and the spring of the oil relief poppet valve is pressed against the control valve body next to it. A solenoid valve spring is installed on the valve stem, and the solenoid valve spring is connected to the oil return hole, and the second oil circuit connected to the first oil circuit is set in the control valve body, and the valve stem of the oil discharge poppet intersects with the second oil circuit; The oil outlet valve includes a high-pressure oil pipe connection port arranged up and down and an oil outlet valve spring, and the second oil circuit is connected to the high-pressure oil pipe connection port through the oil outlet valve spring.

The present invention may also include:

1. The first pressure receiving surface and the second pressure receiving surface are respectively set on the part of the stem of the oil discharge poppet valve that intersects with the second oil passage, and the first pressure receiving surface and the second pressure receiving surface are respectively located On the side of the oil cone valve and the spring side of the oil discharge cone valve, the area of the first pressure receiving surface is not less than 1.2 times the area of the second pressure receiving surface.

The advantage of the present invention is that: the traditional normally open electronically controlled high-pressure oil pump realizes the control of the oil supply time and the oil supply amount by controlling the moment and time when the oil drain valve closes the oil drain circuit through the solenoid valve, but there is a power failure of the engine. The disadvantage of not working properly after a failure. This device can solve this problem very well: the fuel control valve of this device is a normally closed control valve. When the solenoid valve is not powered on, the oil discharge cone valve is in the closed state, and the oil discharge cone valve is controlled by the solenoid valve to open the oil discharge oil. The time and time of the road are used to control the timing and amount of fuel supply. During normal operation, this device can quickly and accurately control the flow rate and time of fuel passing through the fuel control valve. Flexible control of oil quantity. At the same time, the normally closed oil drain valve of the device is in a closed state when the electromagnetic valve fails, and the high pressure oil pump can still continue to complete the oil supply function. When the solenoid valve fails, under the action of the gear rod, the device pulls the rotary sleeve through the ring gear to control the relative position of the helical groove of the plunger and the oil inlet and return holes to control the oil supply time and oil supply volume. In order to improve the safety of the fuel control valve, the oil discharge cone valve of this device is designed with protection measures. When the solenoid valve fails and cannot be powered on, or when the hydraulic device such as the injector connected to the high-pressure oil pump fails, the oil discharge cone valve is in The normally closed state will cause the pressure in the normally closed solenoid valve to continue to rise, but under the action of protective measures, the oil drain poppet valve will open the oil drain circuit, so that the fuel flows back to the low-pressure fuel tank, reducing the fuel pressure in the entire system and protecting Fuel system safety.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the structural representation of roller plunger of the present invention;

Fig. 3a is a schematic structural diagram of a normally closed fuel control valve of the present invention, and Fig. 3b is a partial schematic diagram of Fig. 3a;

Fig. 4 is a structural schematic diagram of the oil delivery valve of the present invention.

Detailed ways

The present invention is described in more detail below in conjunction with accompanying drawing example:

Referring to Figures 1-4, the device includes a roller plunger 1, a normally closed fuel control valve 2 and an oil outlet valve 3. The roller plunger 1 is installed at the bottom of the pump body 4, and is composed of a roller 5, a plunger 6, a plunger spring 7, a ring gear 8, a gear rod 9, an oil inlet 10, an oil return hole 11 and a plunger chamber 12. A normally closed fuel control valve is installed above the plunger chamber 12, including a solenoid valve 13, a solenoid valve stem 14, a solenoid valve spring 15, an oil drain cone valve connecting sleeve 16, an oil drain cone valve 17, and an oil drain cone valve Valve stem 18 and oil discharge cone valve spring 19. The oil outlet valve 5 is installed on the top of the pump body 1 and consists of an oil outlet valve spring 22 and a high-pressure oil pipe connection port 23 .

When the solenoid valve works normally, the fuel enters the plunger chamber 12 from the oil inlet hole 10, and the cam pushes the roller 5 to make the plunger 6 go up. After closing the oil inlet hole 10, the fuel oil in the plunger chamber 12 is compressed to complete the oil pressure function. The normally closed fuel control valve 2 includes a solenoid valve 13, a solenoid valve stem 14, a solenoid valve spring 15, an oil drain cone valve connecting sleeve 16, an oil drain cone valve 17, an oil drain cone valve stem 18 and an oil drain cone valve Spring 19. The solenoid valve 13 is installed at the leftmost end of the normally closed fuel control valve 2, and it is connected with the oil drain cone valve 17 through the interference fit of the solenoid valve stem 14 and the oil drain cone valve connecting sleeve 16 at the top of the oil drain cone valve stem 18 . When the solenoid valve 13 of the normally closed fuel control valve 2 is not powered on, the oil drain poppet valve 17 receives the spring force F1 transmitted by the solenoid valve spring 15 through the solenoid valve stem 14, and the oil drain poppet valve spring 19 acts on the oil drain poppet valve. The spring force F2 on the valve stem 18, and the fuel pressure P. Both the solenoid valve spring 15 and the oil discharge cone valve spring 19 are in a compressed state. Since the preload force F1 of the solenoid valve spring 15 is greater than the preload force F2 of the oil discharge cone valve spring 19, that is, F ₁ > F ₂ , the oil discharge cone valve 17 Seat on the cone surface, the drain oil passage of the normally closed fuel control valve 2 is in the normally closed state, and the fuel compressed by the plunger 6 in the plunger chamber 12 flows to the oil outlet valve 3 through the oil passage L2. When the fuel pressure P is greater than the spring preload of the fuel outlet valve spring 22 , the fuel enters the fuel injector through the high-pressure fuel pipe connected to the high-pressure fuel pipe interface 23 . When the solenoid valve 13 is powered on, the drain cone valve 17 is subjected to the resultant force of the electromagnetic force F3 generated by the solenoid valve 13, the spring force F1 of the solenoid valve spring 15, the spring force F2 of the drain cone valve spring 19 and the fuel pressure P, and the electromagnetic force F3 The resultant force of the spring force F2 of the oil discharge cone valve spring 19 is greater than the rightward spring force F1 of the solenoid valve spring 15, that is, F ₃ +F ₂ >F ₁ , the solenoid valve stem 14 pulls the oil discharge cone valve 17 to lift up and open the oil discharge Oil circuit L1, the fuel flows back to the low-pressure fuel tank through the oil return hole 11 through L1, and the high-pressure fuel pump stops supplying fuel.

When the failure solenoid valve 13 such as power failure occurs in the engine and cannot be powered on, the oil drain poppet valve 17 is in a normally closed state, and can still continue to complete the fuel supply function, which can improve the reliability of the fuel system and improve the working stability of the engine. At the same time, the high-pressure oil pump can control the oil supply through the mechanical gear rod plunger. When the roller 5 pushes the plunger 6 to move upward, the upper edge of the plunger 6 closes the oil inlet hole 10 on the plunger sleeve and starts to pressurize the fuel. When the plunger 6 continues to rise, the spiral groove of the plunger 6 opens to return oil Orifice 11, under high pressure fuel flows from the plunger chamber 12 back to the fuel tank. By pulling the gear rod 9, the ring gear 8 drives the plunger rotary sleeve to rotate the plunger 6, which can change the time for the helical groove of the plunger 6 to open the oil return hole 11, and then change the oil supply end time, and complete the adjustment of the oil supply time and the oil supply. Adjustment of oil quantity.

When the solenoid valve 13 of the normally closed fuel control valve 2 fails to work, the drain oil circuit cannot be opened, and the fuel continuously flows into the injector from the oil inlet circuit, causing the normally closed fuel control valve and injectors and other Increasing fuel pressure in the hydraulic unit can cause damage to the fuel system and engine. In order to solve this problem, the normally closed fuel control valve 2 of the device is designed with a safety protection device. The fuel pressure pressure surface of the oil discharge cone valve 17 is composed of a pressure surface 20 and a pressure surface 21 . In a traditional normally open fuel control valve, these two pressure receiving surfaces have the same area, and the drain poppet is subjected to balanced hydraulic pressure. In the normally closed fuel control valve, the fuel oil circuit at the oil discharge cone is designed to be stepped, which increases the area of the pressure receiving surface 20 so that the area ratio of the area of the pressure receiving surface 21 to that of the pressure receiving surface is greater than 1.2. The pressure F 20 at the pressure receiving surface ₂₀ >1.2F ₂₁ , when the fuel pressure increases to a certain level, F ₂₀ +F ₂ >F ₂₁ +F ₁ , the oil drain cone valve 17 will be opened, and the fuel will be drained The oil circuit flows back to the low-pressure fuel tank, which reduces the fuel pressure in the system and protects the safety of normally closed valves and other hydraulic devices.

The invention relates to a normally closed electromechanical composite high-pressure oil pump, which comprises a roller plunger 1, a normally closed fuel control valve 2 and an oil outlet valve 3. The normally closed electromechanical composite high-pressure oil pump has a roller plunger 1 installed at the bottom of the pump body 4, consisting of a roller 5, a plunger 6, a plunger spring 7, a ring gear 8, a gear rod 9, an oil inlet hole 10, and an oil return The hole 11 is composed of the plunger chamber 12, wherein the plunger is designed with a spiral groove. A normally closed fuel control valve 2 is installed above the roller plunger, and an oil outlet valve is installed on the top of the pump body 4 . The normally closed fuel control valve 2 can electromagnetically control the high-pressure oil pump, and the roller plunger can mechanically control the high-pressure oil pump when the electromagnetic control fails. The normally closed fuel control valve includes: a solenoid valve 13, a solenoid valve stem 14, a solenoid valve spring 15, an oil drain cone valve connecting sleeve 16, an oil drain cone valve 17, an oil drain cone valve stem 18 and a drain valve. Oil cone valve spring 19. The solenoid valve 13 is connected with the oil discharge cone valve 17 through the interference fit of the solenoid valve stem and the oil discharge cone valve connecting sleeve 16 . It is in a normally closed state when it is not powered on, and after power on, it opens the oil drain oil circuit by controlling the oil drain poppet valve 17 to complete oil drain. In the normally closed fuel control valve, the fuel oil passage at the oil discharge cone is designed in a stepped shape, which increases the area of the pressure receiving surface 20 so that the area ratio of the area of the pressure receiving surface 21 to the area of the pressure receiving surface is greater than 1.2. When the fuel pressure is too high, the different forces caused by the different stress areas at both ends can open the oil discharge cone valve to complete the oil discharge and protect the safety of the system.

Claims (2)

1. the electromechanical combined formula high pressure oil pump of normal close type, is characterized in that: comprise roller plunger, normal close type fuel regulator valve, outlet valve, roller plunger comprises the pump housing, plunger bushing, housing, plunger, roller, plunger bushing is arranged in housing, the pump housing is arranged on below housing, cover has the plunger of piston spring, its upper part is positioned in plunger bushing, its underpart is positioned in the pump housing, piston spring upper end withstands on plunger bushing, piston spring lower end withstands in the pump housing, inner walls arranges ratch, plunger bushing outer wall arranges the gear ring matched with ratch, plunger cavity is formed between the plunger jacket wall of plunger and its upper end, plunger bushing arranges oil inlet hole, spill port and the first oil circuit, the sidewall in its upper end portion is arranged to control plunger cavity and spill port logical, disconnected spiral chute, normal close type fuel regulator valve comprises control valve body, electromagnetic valve body, solenoid valve valve rod, draining cone valve, draining cone valve valve rod, control valve body and electromagnetic valve body are arranged in juxtaposition, draining cone valve, draining cone valve valve rod is arranged in control valve body, electromagnetic valve body connects the first end of draining cone valve by solenoid valve valve rod, second end of draining cone valve is tapered end face, tapered end face coordinates with the control valve body on its side, draining cone valve valve rod first end connects the second end of draining cone valve, second end of draining cone valve valve rod withstands on draining cone valve spring, draining cone valve spring top is on the control valve body that it is other, solenoid valve valve rod is provided with solenoid valve spring, solenoid valve spring place is communicated with spill port, the second oil circuit communicated with the first oil circuit is set in control valve body, draining cone valve valve rod intersects mutually with the second oil circuit, outlet valve comprises the high-pressure oil pipe connection mouth and oil outlet valve spring arranged up and down, and the second oil circuit connects high-pressure oil pipe connection mouth by oil outlet valve spring.

2. the electromechanical combined formula high pressure oil pump of normal close type according to claim 1, it is characterized in that: the part that draining cone valve valve rod intersects with the second oil circuit arranges the first compression face and the second compression face respectively, first compression face and the second compression face lay respectively at draining cone valve side and the draining cone valve spring side of the second oil circuit, and the area of the first compression face is not less than 1.2 times of the second compression face area.