A fast-switching fuel injector control valve

Abstract

The present invention discloses a fast-switching fuel injector control valve, which includes a valve sleeve and a plunger inserted into the central hole of the valve sleeve. A control chamber is formed between the plunger and the valve sleeve. The valve sleeve is provided with a valve sleeve inlet throttle hole and a valve sleeve outlet throttle hole; a switch valve body is installed in the control chamber, and the switch valve body divides the control chamber into a control chamber upper chamber and a control chamber lower chamber; a central hole is provided at the lower end of the switch valve body, and a return spring is installed in the central hole; a switch valve outlet throttle hole is provided at the center of the upper end of the switch valve body, and two switch valve inlet throttle holes are symmetrically provided outside the switch valve outlet throttle hole. The fuel injector adopting the above technical solution can change the A / Z ratio of opening / closing through the design of the switch valve structure, achieve the purpose of slow opening and fast closing, and conform to the fuel injection law of "slow first and then urgent".

Description

Technical Field

[0001] The invention belongs to the technical field of fuel injectors, and in particular relates to a fast switching fuel injector control valve. Background Art

[0002] If the internal combustion engine wants to further improve thermal efficiency, reduce power loss, and have higher requirements on injection rules, it is necessary to upgrade the injector technology from a structure with high-pressure static fuel leakage in the gap between the mating parts to a structure without high-pressure static leakage.

[0003] The injector without static leakage usually has only one control valve pair, with a high pressure chamber and a control chamber at both ends of the pair, such as Figure 1 . This type of injector has a disadvantage, that is, the needle valve rises faster when it is opened, and falls slower when it is seated. This causes the injection pattern to be fast first and slow later, which is exactly the opposite of the ideal "slow first and fast later" injection pattern. The pressure in the control chamber of the existing ordinary control valve is only affected by the A / Z (A represents the oil outlet throttle hole, and Z represents the oil inlet throttle hole) of the valve sleeve, and the ideal injection rate requirement of slow first and fast later cannot be met by a single control strategy. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a fast-switch fuel injector control valve for achieving the purpose of slow opening and fast closing.

[0005] The present invention is implemented as follows: a fast switching injector control valve comprises a valve sleeve (1), a plunger (2) inserted in a center hole of the valve sleeve, a control chamber (C) formed between the plunger and the valve sleeve, a valve sleeve oil inlet throttling hole (Z1) and a valve sleeve oil outlet throttling hole (A1) provided on the valve sleeve, wherein the valve sleeve oil inlet throttling hole (Z1) is located on the side wall of the valve sleeve and communicates with the control chamber, and the valve sleeve oil outlet throttling hole is located at the center top of the sleeve and communicates with the control chamber (C); the characteristic is that a switch valve body (3) is installed in the control chamber (C), and the switch valve body The control chamber is divided into an upper chamber (C2) and a lower chamber (C1), wherein the upper chamber (C2) is connected to the oil inlet throttling hole (Z1) of the valve sleeve; a center hole is provided at the lower end of the switch valve body, a return spring is installed in the center hole, the upper end of the return spring abuts against the bottom of the center hole, and the lower end surface of the return spring abuts against the upper end surface of the plunger (2); a switch valve oil outlet throttling hole (A2) is provided at the center of the upper end of the switch valve body, and two switch valve oil inlet throttling holes (Z2) are symmetrically provided on the outer side of the switch valve oil outlet throttling hole (A2);

[0006] The ratio between the switch valve oil inlet throttle hole Z2 and the switch valve oil outlet throttle hole A2 of the switch valve body is different from the ratio between the valve sleeve oil inlet throttle hole Z1 and the valve sleeve oil outlet throttle hole A1. The valve sleeve A1 / Z1 ratio should be greater than the switch valve A2 / Z2.

[0007] Preferably, the outer diameter (D1) of the switch valve body (3) is equal to the plunger diameter (d2).

[0008] Preferably, the flow rate of the valve sleeve oil inlet throttle hole (Z1) and the valve sleeve oil outlet throttle hole (A1) of the valve sleeve is greater than that of the switch valve oil inlet throttle hole (Z2) and the switch valve oil outlet throttle hole (A2) of the switch valve body.

[0009] Advantages and technical effects of the present invention:[[]]END]]

[0010] The injector adopting the above technical solution can achieve the fuel injection law of "slow first and then fast". Specifically, when the solenoid valve is opened, the rising speed of the plunger is controlled by the A2 / Z2 ratio of the switch valve body; when the solenoid valve is closed, the falling speed of the plunger is controlled by the A1 / Z1 ratio of the valve sleeve. Furthermore, by changing the A / Z ratio of opening / closing through the structural design of the switch valve, the purpose of slow opening and fast closing is achieved. Description of the drawings

[0011] Figure 1 is a schematic structural diagram of the present invention;

[0012] Figure 2 is Figure 1 the enlarged structural diagram of part I in

[0013] Figure 3 is a schematic structural diagram of the prior art.

[0014] In the figure, 1, valve sleeve; 2, plunger; 3, switch valve body; 4, return spring;

[0015] C, control chamber; C1, lower chamber of the control chamber; C2, upper chamber of the control chamber;

[0016] A1, valve sleeve oil outlet throttle hole; A2, switch valve oil outlet throttle hole;

[0017] Z1, valve sleeve oil inlet throttle hole; Z2, switch valve oil inlet throttle hole. Specific embodiments

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Please refer to Figure 1 and Figure 2, A fast-switching fuel injector control valve, comprising a valve sleeve 1 and a plunger 2 inserted into the central hole of the valve sleeve. A control chamber C is formed between the plunger and the valve sleeve. The valve sleeve is provided with a valve sleeve inlet throttle hole Z1 and a valve sleeve outlet throttle hole A1. The valve sleeve inlet throttle hole Z1 is located on the side wall of the valve sleeve and communicates with the control chamber. The valve sleeve outlet throttle hole is located at the top of the sleeve center and communicates with the control chamber C. A switch valve body 3 is installed in the control chamber C. The switch valve body divides the control chamber into an upper control chamber C2 and a lower control chamber C1. The upper control chamber C1 communicates with the valve sleeve inlet throttle hole Z1. A central hole is provided at the lower end of the switch valve body. A return spring is installed in the central hole. The upper end of the return spring abuts against the bottom of the central hole, and the lower end face of the return spring abuts against the upper end face of the plunger 2. A switch valve outlet throttle hole A2 is provided at the center of the upper end of the switch valve body. Two switch valve inlet throttle holes Z2 are symmetrically provided outside the switch valve outlet throttle hole A2.

[0020] Preferably, the outer diameter D1 of the switch valve body 3 is equal to the diameter d2 of the plunger.

[0021] Preferably, the flow rate of the valve sleeve inlet throttle hole Z1 and the valve sleeve outlet throttle hole A1 of the valve sleeve is greater than that of the switch valve inlet throttle hole Z2 and the switch valve outlet throttle hole A2 of the switch valve body.

[0022] The working principle and control method of the present invention:

[0023] The ratio of the inlet throttle hole Z1 and the outlet throttle hole A1 of the valve sleeve 1 needs to be respectively matched with the inlet throttle hole Z2 and the outlet throttle hole A2 of the switch valve body 3. The A1 / Z1 ratio of the valve sleeve should be > the A2 / Z2 ratio of the switch valve. Match the two A / Z ratios according to the injection rate curve. The A1 / Z1 ratio should be 0.43 larger than the A2 / Z2 ratio.

[0024] When the fuel injector is working, the solenoid valve is opened, and the pressure in the upper control chamber C1 is rapidly reduced through the switch valve body 3 outlet throttle hole A2. The pressure difference between the inside and the lower control chamber causes the switch valve body 3 to move downward. The switch valve inlet throttle hole Z2 starts to supplement the pressure to the upper control chamber C2. Finally, the rising speed of the plunger 2 is controlled through the inlet and outlet throttle holes of the switch valve body 3 to achieve the purpose of "slow" lifting.

[0025] When the solenoid valve is closed, the valve sleeve inlet throttle hole Z1 supplements the pressure in the lower control chamber C1, and supplements the pressure to the upper control chamber C2 through the switch valve body 3 inlet Z2 and outlet A2 to achieve the purpose of "fast" closing.

[0026] After controlling the pressure balance between the upper control chamber C2 and the lower control chamber C1, the switch valve body 3 is reset to the inner end face of the valve sleeve 1 through the return spring 4.

[0027] The flow rates of the valve sleeve oil inlet throttle hole Z1 and the valve sleeve oil outlet throttle hole A1 of the valve sleeve 1 should be significantly greater than those of the switching valve oil inlet throttle hole Z2 and the switching valve oil outlet throttle hole A2 of the switching valve body 3.

[0028] In summary, the injector assembled by the present invention can achieve the injection law of "slow first and then fast". Specifically, when the solenoid valve is opened, the rising speed of the plunger is controlled by the A2 / Z2 ratio of the switching valve body; when the solenoid valve is closed, the falling speed of the plunger is controlled by the A1 / Z1 ratio of the valve sleeve. Furthermore, by changing the A / Z ratio of opening / closing through the design of the switching valve structure, the purpose of slow opening and fast closing is achieved.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fast-switching fuel injector control valve, comprising a valve sleeve (1) and a plunger (2) inserted into the central hole of the valve sleeve. A control chamber (C) is formed between the plunger and the valve sleeve. The valve sleeve is provided with a valve sleeve inlet throttle hole (Z1) and a valve sleeve outlet throttle hole (A1). The valve sleeve inlet throttle hole (Z1) is located on the side wall of the valve sleeve and communicates with the control chamber. The valve sleeve outlet throttle hole is located at the top of the sleeve center and communicates with the control chamber (C); characterized in that: A switch valve body (3) is installed in the control chamber (C). The switch valve body divides the control chamber into an upper control chamber (C2) and a lower control chamber (C1). The upper control chamber (C2) is communicated with an oil inlet throttle hole (Z1) of the valve sleeve. A central hole is provided at the lower end of the switch valve body. A return spring is installed in the central hole. The upper end of the return spring abuts against the bottom of the central hole, and the lower end face of the return spring abuts against the upper end face of the plunger (2). A switch valve oil outlet throttle hole (A2) is provided at the center of the upper end of the switch valve body. Two switch valve oil inlet throttle holes (Z2) are symmetrically provided outside the switch valve oil outlet throttle hole (A2). The ratio between the switch valve oil inlet throttle hole (Z2) and the switch valve oil outlet throttle hole (A2) of the switch valve body is different from the ratio between the valve sleeve oil inlet throttle hole (Z1) and the valve sleeve oil outlet throttle hole (A1). The ratio of A1 / Z1 of the valve sleeve should be > A2 / Z2 of the switch valve. The outer diameter (D1) of the switch valve body (3) is equal to the diameter of the plunger (d2). The flow rate of the valve sleeve oil inlet throttle hole (Z1) and the valve sleeve oil outlet throttle hole (A1) of the valve sleeve is greater than that of the switch valve oil inlet throttle hole (Z2) and the switch valve oil outlet throttle hole (A2) of the switch valve body.

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