CN111238821A - Measuring system for engine crankshaft position - Google Patents

Abstract

The invention discloses a measuring system for the position of an engine crankshaft, which comprises a motor, wherein the motor comprises a stator and a rotor sleeved outside the stator, the stator is provided with a stator core and a coil winding, a plurality of teeth are arranged on the stator core in a circular manner, and the coil winding is wound on the teeth; the rotor is provided with a rotor shell which is sleeved outside the stator core, the inner wall of the rotor shell is annularly provided with a plurality of conventional magnetic steels, and the conventional magnetic steels are also distributed according to the N-S polarity alternating sequence; a Hall device is also arranged on the stator iron core; a different magnet is also arranged between two adjacent conventional magnetic steels, the different magnet is provided with two magnetic steel blocks which are axially arranged along the rotor shell and fixedly connected into a whole, and the polarities of the two magnetic steel blocks are different. The measuring system for the engine crankshaft position not only can accurately judge the engine crankshaft position, but also can realize the accurate control of an electronic fuel injection system on fuel injection and ignition; the engine can be made compact in overall structure and low in cost.

Description

Measuring system for engine crankshaft position

technical field

The invention relates to the technical field of engines, and in particular provides a measuring system for the position of an engine crankshaft.

Background technique

Usually, the crankshaft position detection required at the time of engine ignition or fuel injection is provided by the pulse trigger. However, due to the limitation of the engine installation space and other conditions, there is an urgent need for a method that can accurately measure the position of the crankshaft. Measuring system with compact structure and saving installation space.

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

In order to overcome the above defects, the present invention provides a measurement system for the position of the engine crankshaft, which can not only accurately determine the position of the engine crankshaft, and realize the precise control of fuel injection and ignition by the electronic fuel injection system; and cost reduction.

The technical solution adopted by the present invention in order to solve the technical problem is: a measuring system for the position of the crankshaft of an engine, comprising a motor, the motor comprising a stator and a rotor sleeved outside the stator, wherein the stator has a stator iron Core and coil windings, a plurality of teeth are arranged in a ring on the stator iron core, and the coil windings are wound on a plurality of the teeth; the rotor has a set of rotor casings arranged outside the stator iron core , a plurality of conventional magnetic steels are arranged in a ring on the inner wall of the rotor casing, and the plurality of conventional magnetic steels are also distributed in an alternating sequence of N-S polarities; on the stator iron core, there are also installed on the stator iron core capable of generating Hall signals There is also a different magnet between two adjacent conventional magnetic steels, and the different magnet has two magnetic steel blocks arranged in the axial direction of the rotor shell and fixedly connected into one body, And the polarities of the two magnetic steel blocks are different.

As a further improvement of the present invention, a tooth slot is formed between every two adjacent teeth; the Hall device is one, which is installed in one of the tooth slots.

As a further improvement of the present invention, the Hall device adopts a Hall sensor.

As a further improvement of the present invention, the axial direction of the rotor casing is defined as the up-down direction, and correspondingly, the two magnetic steel blocks arranged in the up-down direction are respectively defined as an upper magnetic steel block and a lower magnetic steel block;

Wherein, the polarity of the upper magnetic steel block is the same as the polarity of the two adjacent conventional magnetic steels, and the polarity of the lower magnetic steel block is the same as the polarity of the adjacent two conventional magnetic steels on the contrary.

As a further improvement of the present invention, the geometric dimensions of the upper magnetic steel block and the lower magnetic steel block are inconsistent.

As a further improvement of the present invention, the center line of the vertical section of the upper magnetic steel block coincides with the center line of the vertical section of the lower magnetic steel block.

As a further improvement of the present invention, the center line of the vertical section of the upper magnetic steel block deviates from the center line of the vertical section of the lower magnetic steel block.

The beneficial effects of the present invention are as follows: (1) By using the abnormal waveform generated when the Hall device rotates the different magnet, the position of the crankshaft of the engine can be accurately determined, so that the precise control of the fuel injection and ignition by the electronic fuel injection system can be realized . ② Compared with the prior art, the present invention eliminates the components such as the pulse trigger and the boss on the rotor, which can reduce the size of the motor and the installation space of the motor, so as to realize the compactness of the overall structure of the engine. It provides convenient conditions; on the other hand, it also effectively reduces the processing cost of the rotor and the engine case, thereby realizing the low cost of the overall engine cost.

Description of drawings

1 is a schematic cross-sectional structure diagram of the engine crankshaft position measurement system according to the present invention;

Figure 2a is a schematic diagram of the shape and polarity of the dissimilar magnet according to the first embodiment of the present invention;

Figure 2b is a schematic diagram of the shape and polarity of the second embodiment of the dissimilar magnet of the present invention;

Figure 2c is a schematic diagram of the shape and polarity of the dissimilar magnet according to the third embodiment of the present invention;

2d is a schematic diagram of the shape and polarity of the dissimilar magnet according to the fourth embodiment of the present invention;

3 is a schematic diagram of the working principle of the engine crankshaft position measurement system according to the present invention when the engine stroke is determined.

In conjunction with the accompanying drawings, the following descriptions are made:

10—stator; 100—stator core; 101—coil winding; 11—rotor; 110—rotor shell; 111—conventional magnet; 112—different magnet; 1120—upper magnet block; 1121—lower magnet block; 2 - Hall devices.

Detailed ways

The embodiments of the present invention are described below by means of specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

It should be noted that the structures, proportions, sizes, etc. shown in the drawings in this specification are only used to cooperate with the contents disclosed in the specification, so as to be understood and read by those who are familiar with the art, and are not used to limit the implementation of the present invention. Restricted conditions, it does not have technical substantive significance, any structural modification, proportional relationship change or size adjustment, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the present invention. The scope of the disclosed technical content can be covered.

Example:

Please refer to FIG. 1 , which is a schematic cross-sectional structure diagram of the engine crankshaft position measurement system according to the present invention.

The system for measuring the position of the engine crankshaft according to the present invention includes an electric motor including a stator 10 and a rotor 11 sleeved outside the stator 10 , wherein the stator 10 has a stator iron core 100 and a coil winding 101 . The stator core 100 is provided with a number of teeth in a ring, and the coil winding 101 is wound on the teeth; the rotor 11 has a set of rotor casings 110 arranged outside the stator core 100, so Several conventional magnetic steels 111 are arranged in a ring on the inner wall of the rotor casing 110, and the several conventional magnetic steels 111 are also distributed in an alternating sequence of N-S polarities; A Hall device 2 capable of generating a Hall signal; a different magnet 112 is also provided between two adjacent conventional magnetic steels 111 , and the different magnet 112 has two axially arranged along the rotor housing 110 , And fixedly connected into an integrated magnetic steel block, and the polarities of the two magnetic steel blocks are different.

In this embodiment, preferably, a tooth slot is formed between every two adjacent teeth; the Hall device 2 is one, which is installed in one of the tooth slots.

Further preferably, the Hall device 2 adopts a Hall sensor.

In this embodiment, preferably, the axial direction of the rotor housing 110 is defined as the up-down direction, and correspondingly, the two magnetic steel blocks arranged in the up-down direction are defined as the upper magnetic steel block 1120 and the lower magnetic steel block 1120 respectively. Steel block 1121; wherein, the polarity of the upper magnetic steel block 1120 is the same as the polarity of the two adjacent conventional magnetic steels 111, and the polarity of the lower magnetic steel block 1121 is the same as the polarity of the adjacent two adjacent magnetic steel blocks 1121. The polarities of the conventional magnetic steel 111 are opposite, as shown in FIG. 2a to FIG. 2d for details. In addition, it is added that: if the conventional magnetic steel is a single-pole magnetic steel, the polarity of the upper magnetic steel block (lower magnetic steel block) is the same (opposite) to the polarities of the two conventional magnetic steels; If the conventional magnetic steel is arc-shaped magnetic steel, the polarity of the upper magnetic steel block (lower magnetic steel block) is the same (opposite) to the polarity of the adjacent ends of the two conventional magnetic steels.

Further preferably, the geometric dimensions of the upper magnetic steel block 1120 and the lower magnetic steel block 1121 are inconsistent. The center line of the vertical section of the upper magnetic steel block 1120 coincides with the center line of the vertical section of the lower magnetic steel block 1121; The centerlines of the vertical sections of the steel blocks 1121 are deviated from each other; for details, please refer to FIGS. 2 a to 2 d .

In addition, the present invention also provides the working principle of the engine crankshaft position measurement system, specifically: every time the motor rotor rotates one circle, the Hall device 2 will generate high and low levels with the polarity conversion of the magnetic steel Interconverted waveforms. When the Hall device 2 rotates through the different magnet 112, an abnormal waveform (different from the conventional magnetic steel 111) will be generated. This abnormal waveform has a fixed positional relationship with the crankshaft of the engine, as shown in FIG. 3, that is, Every two rotations (720°) of the rotor, the Hall device 2 will provide two sets of crankshaft position signals, wherein the signals generated by the different magnets 112 are different from those generated by the conventional magnetic steel 111. Therefore, The EFI software can use this abnormal signal to determine the reference position and four strokes of the engine crankshaft, and then calculate the precise fuel injection time and ignition timing according to the program.

In addition, the method for determining the four strokes of the engine is described as follows: First, find the reference position of the engine through the assembly position relationship between the dissimilar magnet 112 and the crankshaft, and after finding the reference position of the engine, rotate the motor twice (that is, rotate 720 The Hall signals in °) are defined as No. 0 to No. 11 respectively. Find the two Hall signals corresponding to No. 0 and No. 6, and compare the passing time of the two Hall signals to distinguish them. Compression top dead center and exhaust top dead center, and then determine the intake and power strokes, so that fuel injection and ignition can be performed in the compression stroke corresponding to the No. 6 waveform, so as to start the engine and realize the fuel injection by the EFI system. With precise control of ignition.

To sum up, the measurement system of the present invention can accurately determine the position of the crankshaft of the engine by using the abnormal waveform generated when the Hall device rotates through the different magnet, so that the fuel injection and ignition of the electronic fuel injection system can be realized. precise control. Moreover, compared with the prior art, the present invention eliminates the components such as the pulse trigger and the boss on the rotor, which can reduce the external size of the motor and the installation space of the motor, so as to realize the compactness of the overall structure of the engine. It provides convenient conditions; on the other hand, it also effectively reduces the processing cost of the rotor and the engine case, thereby realizing the low cost of the overall engine cost.

The above-mentioned embodiments are only used to illustrate the effect of the present invention, rather than to limit the present invention. Improvements and modifications should also be considered within the scope of the present invention.

Claims (7)

1. The measuring system for the position of the crankshaft of the engine comprises a motor, wherein the motor comprises a stator (10) and a rotor (11) sleeved outside the stator (10), the stator (10) is provided with a stator core (100) and a coil winding (101), a plurality of teeth are arranged on the stator core (100) in a row, and the coil winding (101) is wound on the teeth; the rotor (11) is provided with a rotor shell (110) which is sleeved outside the stator core (100), a plurality of conventional magnetic steels (111) are arranged on the inner wall of the rotor shell (110) in a circular array mode, and the conventional magnetic steels (111) are further distributed according to an N-S polarity alternating sequence; the method is characterized in that: a Hall device (2) capable of generating Hall signals is further mounted on the stator core (100); a different magnet (112) is further arranged between two adjacent conventional magnetic steels (111), the different magnet (112) is provided with two magnetic steel blocks which are axially arranged along the rotor shell (110) and fixedly connected into a whole, and the polarities of the two magnetic steel blocks are different.

2. The system of claim 1, wherein: tooth grooves are formed between every two adjacent teeth; the Hall device (2) is one and is arranged in the tooth groove.

3. The system of claim 2, wherein: the Hall device (2) adopts a Hall sensor.

4. The system of claim 1, wherein: defining the axial direction of the rotor shell (110) as an up-down direction, and correspondingly, respectively defining two magnetic steel blocks arranged along the up-down direction as an upper magnetic steel block (1120) and a lower magnetic steel block (1121);

the polarity of the upper magnetic steel block (1120) is the same as that of the two adjacent conventional magnetic steels (111), and the polarity of the lower magnetic steel block (1121) is opposite to that of the two adjacent conventional magnetic steels (111).

5. The system of claim 4, wherein: the upper magnetic steel block (1120) and the lower magnetic steel block (1121) are different in size in geometric dimension.

6. The system of claim 5, wherein: the central line of the vertical section of the upper magnetic steel block (1120) is coincided with the central line of the vertical section of the lower magnetic steel block (1121).

7. The system of claim 5, wherein: the center line of the vertical section of the upper magnetic steel block (1120) deviates from the center line of the vertical section of the lower magnetic steel block (1121).

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