CN204299726U - A kind of motorcar electric EGR valve - Google Patents

Abstract

An electric EGR valve for automobiles, the valve seat is provided with an air inlet and an air outlet; the air inlet and the air outlet are connected through a channel; the inside of the valve seat is provided with a long hole communicating with the inner cavity, and the valve stem is arranged in the inner cavity and the long hole The rise of the valve stem can block the passage, and the fall of the valve stem can open the passage; the top of the housing is equipped with an inwardly recessed end cover; it also includes a screw drive assembly; The rotor inside the stator and the screw; the rotor is provided with a threaded hole, and a screw is arranged in the threaded hole, and the lower end of the screw extends into the inner cavity below the end cover and is connected with the top of the valve stem. The beneficial effect of the utility model is that the moving distance of the valve stem can be uniquely determined directly by the rotation angle of the motor, and then the opening degree and the intake air volume of the passage can be controlled without setting a feedback link. The screw drive assembly is connected up and down with the casing, which greatly reduces the volume of the valve and reduces the occupied space.

Description

A kind of automobile electric EGR valve

technical field

The utility model belongs to the field of engine exhaust emission and recirculation systems, in particular to an electric EGR valve for automobiles.

Background technique

In the engine exhaust gas recirculation system (EGR system), the EGR valve is mainly used to adjust and control the flow of recirculated exhaust gas. The electric EGR valve controls the opening of the intake port through the internal DC motor, thereby adjusting the flow of exhaust gas, so that the exhaust gas and fresh The air is mixed in a certain proportion and returned to the cylinder for recirculation, so as to reduce the combustion temperature and combustion speed in the cylinder, and further reduce the emission of NO _X. Compared with the pneumatic EGR valve, the electric EGR valve has the characteristics of fast response and more stable operation, and the electric EGR valve can also solve the problem that some vehicles do not have a vacuum source, so it is widely used.

The electromagnetic EGR valve usually includes a valve seat assembly, the valve stem is installed through the valve seat bushing in the valve seat assembly, the upper end of the valve seat assembly is connected to the shell, and the coil assembly is arranged in the shell, and the inner cavity of the coil assembly passes through the uniform The iron guide sleeve is provided with a uniform iron, and the upper and lower ends of the uniform iron are respectively provided with an upper magnetic plate and a lower magnetic plate. The coil assembly and the upper magnetic plate are pressed tightly by a gland on the top of the shell; the top of the valve stem is close to the uniform iron. The middle part of the valve stem is equipped with a valve stem end cover, and a return spring for resetting the valve stem is arranged between the valve stem end cover and the lower magnetic plate. When the electromagnetic EGR valve is working, a voltage is applied to both ends of the coil assembly, the coil is energized, and a downward magnetic field is generated. Under the action of the magnetic field, the uniform iron drives the valve stem to move downward, and the return spring is compressed to realize the valve action. ; When the two ends of the coil assembly lose power, the valve stem will reset under the action of the return spring. However, the existing electromagnetic EGR valve cannot correctly judge the opening degree of the valve and the stability of the valve stem during the operation process. In the actual operation process, the valve opening can be controlled by controlling the voltage applied to both ends of the coil assembly. Therefore, a device for controlling voltage changes needs to be installed outside the valve, which causes the electromagnetic EGR valve to be bulky and expensive. Waiting is not enough.

Contents of the invention

The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an automobile electric EGR valve with low price, small volume and high control precision.

The technical solution adopted by the utility model to solve the technical problem is: an electric EGR valve for automobiles, including a housing, a valve seat and a valve stem; The air inlet and the air outlet are set on the valve seat; the air inlet and the air outlet are connected through the channel; the inside of the valve seat is provided with a long hole communicating with the inner cavity, and the valve stem is set in the inner cavity and the long hole; the rising of the valve stem can block The channel and the valve stem can be lowered to open the channel; the top of the housing is equipped with an inwardly recessed end cover; it also includes a screw drive assembly; the screw drive assembly includes a stator installed above the end cover, a rotor arranged inside the stator, and a screw; A threaded hole is set on the rotor, and a screw is set in the threaded hole. The lower end of the screw extends into the inner cavity below the end cover and connects with the top of the valve stem; the rotation of the rotor can drive the screw to move up and down; the lower end of the screw is provided with a gland; the gland and the inner A spring is arranged vertically between the bottom of the cavity; the valve stem is located in the spring.

Preferably, the air inlet and the air outlet are opened on the same side, and the air outlet is located above the air inlet.

Preferably, both the internal thread of the threaded hole and the external thread of the screw are trapezoidal threads.

Compared with the prior art, the beneficial effects of the utility model are:

1. The rotation of the rotor drives the screw and the valve stem to move, and the rotor is driven by a stepping motor. The movement distance of the valve stem can be uniquely determined directly by the rotation angle of the motor, and then the opening of the channel and the air intake volume can be controlled. No need to set up a feedback link . The screw drive assembly is connected up and down with the casing, which greatly reduces the volume of the valve and reduces the occupied space.

2. Due to the existence of the spring, the upper side of the screw thread and the lower side of the threaded hole thread are always in close contact, so as to ensure that the backlash of the thread is eliminated when the rotor rotates forward and reverse, thereby improving the control accuracy.

3. The thread adopts trapezoidal thread, which can further increase the width of the tooth profile, thereby improving the precision.

Description of drawings

Fig. 1 is a perspective view of the structure of the utility model;

Fig. 2 is a front view of the structure of the utility model;

Fig. 3 is a sectional view along line A-A in Fig. 2 .

Labeled in the figure:

1 shell; 1.1 inner cavity; 2 end cover; 3 valve seat; 3.1 long hole; 4 air inlet; 5 air outlet; 6 valve stem; 7 gland; 8 stator; 9 screw; 10 rotor; 10.1 threaded hole; 11 springs.

Detailed ways

Below in conjunction with accompanying drawing embodiment, the utility model is described further:

As shown in Figures 1, 2 and 3, an electric EGR valve for an automobile includes a casing 1, a valve seat 3, a valve stem 6 and a screw rod 9 transmission assembly. The valve seat 3 is mounted on the bottom of the housing 1, the top of the housing 1 is provided with an inwardly recessed end cap 2, and the housing 1 is provided with a downwardly recessed inner chamber 1.1. An air inlet 4 and an air outlet 5 are provided on the valve seat 3, and the air inlet 4 and the air outlet 5 are opened on the same side, and the air outlet 5 is located above the air inlet 4, and the air inlet 4 and the air outlet 5 are communicated through passages. The inside of the valve seat 3 is provided with a long hole communicating with the inner cavity 1.1, and the valve stem 6 is arranged in the inner cavity 1.1 and the long hole. The rising of the valve stem 6 can block the passage, and the descending of the valve stem 6 can open the passage. The transmission assembly of the screw 9 is installed on the end cover 2 , and the transmission assembly of the screw 9 includes a stator 8 , a rotor 10 and a screw 9 . The stator 8 is connected to the end cover 2, and the rotor 10 is arranged in the stator 8 and driven by a stepping motor. Threaded hole 10.1 is offered on the rotor 10, screw rod 9 is set in threaded hole 10.1, and the lower end of screw rod 9 extends into the inner chamber 1.1 below the end cover 2 and is connected with the top of valve rod 6; the rotation of rotor 10 can drive screw rod 9 to move up and down. Due to the hysteresis phenomenon in thread fit, there is a very short-term rotation stagnation when the positive and negative rotations are changed, resulting in the situation that the rotation angle of the motor is different from the rotation angle of the screw rod 9 . Therefore, in order to solve this phenomenon, without improving the machining accuracy requirements. A gland 7 can be arranged on the lower end of the screw rod 9; a spring 11 is vertically arranged between the gland 7 and the bottom of the inner chamber 1.1; the valve stem 6 is located in the spring 11. In this way, because the spring 11 is always in a compressed state, regardless of whether the motor is running forward or reverse, the gland 7 is always pushed upward by the spring 11, so that the upper side of the thread of the screw 9 is always tight to the lower side of the thread of the threaded hole 10.1. Tight fit. It is ensured that the motor can drive the screw rod 9 to rotate in time and accurately during forward and reverse rotation, thereby improving the precision.

In order to further improve the accuracy and eliminate the influence of backlash, the internal thread of the threaded hole 10.1 and the external thread of the screw rod 9 are processed into wider trapezoidal threads.

The working principle and working process of the utility model are as follows:

When the EGR valve is working, the transmission assembly of the screw 9 is driven by the motor to drive the screw 9 down, and the valve stem 6 is lowered accordingly to open the passage, and the exhaust gas enters from the air inlet 4 and then enters the intake manifold of the engine through the air outlet 5 , burn again. During the descending process of the screw rod 9 and the valve rod 6, the rotation angle of the stepping motor is controlled by the car chip to automatically control the intake air volume, and there is no need to know the intake air volume through feedback. By controlling the positive and negative rotation of the motor, the screw rod 9 is driven to move up and down, finally controlling the opening of the channel and the intake air volume.

The above is only a preferred embodiment of the utility model, and is not intended to limit the utility model in other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or remodel it into an equivalent change. Equivalent embodiment. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present utility model without departing from the content of the technical solution of the utility model still belong to the protection scope of the technical solution of the utility model.

Claims (3)

1. An electric EGR valve for automobiles, comprising a housing, a valve seat and a valve stem; the valve seat is installed at the bottom of the housing, the housing is provided with a downwardly recessed inner cavity, and an air inlet and an air outlet are provided on the valve seat; The air port and the air outlet are connected through a channel; a long hole communicating with the inner cavity is opened inside the valve seat, and the valve stem is arranged in the inner cavity and the long hole; the rising of the valve stem can block the channel, and the falling of the valve stem can open the channel; it is characterized in that : The top of the housing is equipped with an inwardly recessed end cover; it also includes a screw drive assembly; the screw drive assembly includes a stator installed above the end cover, a rotor arranged inside the stator, and a screw; the rotor is provided with threaded holes, threaded holes The screw rod is arranged in the middle, and the lower end of the screw rod extends into the inner cavity below the end cover and is connected with the top of the valve stem; the rotation of the rotor can drive the screw rod to move up and down; the lower end of the screw rod is set with a gland; the spring is vertically arranged between the gland and the bottom of the inner cavity ;The valve stem is in the spring. 2. A kind of automobile electric EGR valve according to claim 1, characterized in that: the air inlet and the air outlet are opened on the same side, and the air outlet is located above the air inlet. 3. A kind of automobile electric EGR valve according to claim 2, characterized in that: the internal thread of the threaded hole and the external thread of the screw rod are both trapezoidal threads.