Asymmetric magnetization fixture

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention generally relates to an ignition spark timing control device, and more specifically to a device having a magnetic detection capability for timing ignition to the axial position of an engine.

【0002】

[Conventional technology]

Virtually all internal combustion engines manufactured today are equipped with electronic controls that monitor and adjust ignition timing. In the past, functions controlled via various mechanical coupling mechanisms are often controlled in electronic control devices. With this control configuration, it is possible to precisely control the timing of the engine spark and the valve of each cylinder of the fuel injection function. This precision increases the efficiency and responsiveness of the engine to fluctuating operating conditions.

【0003】

The sensors in the current distributors produce one pulse, or one rising edge, for each spark plug that should normally be ignited. Many currently used distributors do not provide the information needed to control the fuel injection system. Moreover, such devices do not give the electronic controller information indicating which spark plug is ignited. In such a device, the electronic controller evaluates the progress of the spark with respect to the operating time of the valve and fuel injector by evaluating the engine speed between the sensor signals and sparks for the calculated time after receiving one sensor signal. Control by delaying.

【0004】

Okada et al., US Pat. No. 4,742,811 discloses an ignition pacing controller using three columns adjacent to the axis of a magnet attached to the shaft. Each magnet column rotates with respect to a Hall sensor that generates a signal at various angles of rotation of the shaft. The first row of magnets are symmetrically spaced around the column. The second row is asymmetrically spaced, while the third row is symmetrically spaced, but distinguished from other pulses by a very small magnetic pole reversal at the end of the pulse. Has one pulse. By processing these three signals via an electronic device, the discriminating ability necessary for the proper functioning of the device is provided.

【0005】

The arrangement of the magnetic columns stacked one after another in Okada's patent requires a considerable minimum height for the aggregate described. In addition, the 24 symmetric poles in the first column indicate that each pole has an angle of 15 ° around the column. This rather large pulse anti-angle equivalence acts to limit the accuracy of the device's function. This inaccuracy is overcome by using three magnetized columns rather than a few columns.

【0006】

Lemen's US Pat. No. 3,373,729 discloses an electronic igniter for an internal combustion engine that uses disks with multiple evenly spaced magnets around the perimeter. This disk is cut perpendicular to the axis so as to form a long groove having two magnets in opposite directions in the axial direction on both sides around the disk. The Hall sensor placed in the long groove generates a trigger signal according to the fluctuating magnetic field received when the disk rotates. This device essentially replaces the breaker points found in standard mechanically timed igniter power distributors. Therefore, the present invention eliminates mechanical contacts and their drawbacks, but does not improve the accuracy of ignition and fuel injection adjustments.

【0007】

[Problems to be Solved by the Invention]

The above indicates the limits known to exist in current devices and methods. Therefore, it is clear that it is convenient to provide alternatives directed to overcome one or more of the aforementioned limitations. Therefore, suitable alternatives are provided that include features that will be described in more detail later.

【0008】

[Means for solving problems]

In one aspect of the invention, it is close to the motion pathways of the first and second magnetic coding means, which are properly mounted to synchronize with the engine, and the first and second magnetic coding means. This is achieved by providing a high resolution sensor device for an internal combustion engine with first and second signal pick-up means in place. The magnetic encoder of the present invention has an electric wire placed on a support in a flat meandering path, and further placed in a conductor loop to change the size, strength and location of each formed magnetic pole. It is made on a magnetized fixture that further has a magnetic field modifier.

【0009】

[Example]

The above and other aspects will become apparent from the following detailed description of the invention when considered in connection with the figures in the accompanying drawings. However, it should be clearly understood that the drawings in the drawings are not intended to limit the invention and are for illustration purposes only.

【0010】

In FIG. 1, a partial elevation view which is a partially sectional view of one embodiment of the present invention is shown. The high resolution detector is preferably designed to be mounted on an existing automotive power distribution base, but is similarly mounted on or anywhere in the engine that can be driven synchronously with the crankshaft or camshaft of the engine. be able to.

【0011】

In this embodiment, a power distribution shaft 1 that protrudes through the fixed power distribution base 2 to which the sensor case 30 is attached and functions to drive a rotating member of the sensor device can be seen. The high resolution magnetic encoder ring 10 is attached to the support plate 20 on which the low resolution magnetic encoder ring 15 rests on the bearing / spacer 35. The encoder rings 10 and 15 have protruding studs 22 that project through holes in the support plate 20 and the drive spring 40. It is attached to the support plate using the magnet holding ring 21. The stud 22 of the magnet holding ring 21 is fixed upside down, threaded or otherwise secured to catch the assembly.

【0012】

The high-resolution sensor 11 and the low-resolution sensor 16 are mounted at appropriate radial positions so as to be aligned with the high-resolution magnetic encoder ring 10 and the low-resolution magnetic encoder ring 15, respectively. These sensors are Hall effect transducers that give an appropriate output regardless of the speed of motion. The signals generated by these sensors are transmitted to the electronic control device of the engine.

【0013】

The upper drive hub 41 is coupled to a power distribution shaft that rotationally drives the hub. A drive spring 40 extends from the upper drive hub 41 to the support plate 20 to make a drive connection between the two plates. The drive spring 40 is designed so that it adapts to a small vertical displacement of the power distribution shaft 1 without causing any relative rotation between the upper drive hub 41 and the support plate 20. This feature is necessary to avoid timing changes that could otherwise be induced by the vertical motion of the switch shaft 1.

【0014】

Cover 51 is provided to protect the sensor device from damage or contamination. An optional seal 52 is provided for the interface between the cover 51 and the distributor shaft 1 and between the sensor case 30 and the distributor shaft 1. These seals may be 0-rings or other suitable sealing tools. The cover 51 is placed on top of the case 30 and secured by gluing or other suitable sealing means. The underside of the case 30 is filled with a castable encapsulant 50 that protects the printed distribution frame of the sensor device and other electronic components.

【0015】

The high-resolution sensor 11 and the low-resolution sensor 16 are shown schematicly in the plan view of FIG. Here, it can be seen that the high resolution sensor consists of two Hall effect transducers and their associated electronic circuits. This provides high resolution by doubling the number of signals generated by the sensor in response to each magnetic pole reversal in the high resolution magnetic encoder ring 10. Only one Hall effect transducer is used in the low resolution sensor 16.

【0016】

FIG. 3 shows a schematic plan view showing the high-resolution magnetic encoder ring 10 and the low-resolution magnetic encoder ring 15. The high resolution encoder ring 10 has a large number of magnetic poles. In a preferred embodiment, the ring will have 360 poles, which may be more or less depending on the requirements of the engine design. The low resolution magnetic encoder ring 15 is shown as an example, assuming that it has 16 poles for a 4-cylinder engine. There are four narrow North Pole, eight intermediate South Pole and four very weak and very wide North Pole. Four narrow North Pole, one for each cylinder, is used to indicate which cylinder is demanding sparks or fuel. This is done by giving magnetic poles in different angular ranges. For example, it is possible to have 1 degree, 2 degree, 3 degree poles representing each cylinder applied. Therefore, in a 4-cylinder engine, the 3 ° magnet would correspond to the 3rd cylinder. Note that all timing is done at the rising edge of the magnetic pulse.

【0017】

The magnet holding ring 21 is shown in FIGS. 4 and 5. From these, it can be seen that the magnet holding ring 21 has an annular shape and has a T-shaped cross section having annular protrusions. The magnet holding ring 21 includes a magnet holding ring and a plurality of protruding studs 22 used for fixing the magnet to the thrust washer plate or the support plate 20. According to the magnet mounting method adopted, the magnet holding ring may also be made with an L-shaped cross section.

【0018】

The protruding stud 22 projects through the gap between the two magnetic coder rings 10 and 15 through the support plate 20 and through the drive spring 40. The drive spring 40 transmits a rotational driving force between the upper drive plate 41 and the support plate 20 connected to the switch shaft 1. It also keeps the contact between the support plate 20 and the bearing / spacer 35 tight.

【0019】

FIG. 6 shows a schematic plan view of the upper drive hub 41, the drive spring 40, the lower drive plate 42, and the protruding stud 22. The drive spring 40 is shown here as having three legs, but it could be similarly shown as having more or less legs according to design requirements.

【0020】

7 and 8 are a plan view and an elevation view of a cross section of a magnetizing instrument 90 used to asymmetrically magnetize a low resolution magnetic encoder ring. The magnetizing appliance 90 is made of a steel base plate 89 on which the electric wire 98 having a flat winding pattern along the surface of the magnetizing instrument is placed. The dimensions of the individual loops in wire 98 are determined by the dimensions of the magnetic poles desired in that loop. When magnetizing an item on this magnetizing instrument, the item will be laid flat on the magnetizing instrument. When a pulse of very large current value passes through wire 98, magnetic poles are created in the steel base plate 89 and in the magnetic material placed on the magnetization device. The aluminum or plastic magnetic field modifier 96 serves two purposes. First, if the magnetic field modifier 96 acts as a spacer for the loop in wire 98, and second, if it is aluminum, it is in the magnetized work piece above the region in the loop of wire 98. Helps to slightly reduce the strength of the North Pole created in. The steel magnetic field modifier 94 acts to increase the magnetic pole strength induced in the workpiece above the modifier, while the aluminum magnetic field modifier 92 weakens the magnetic pole strength and above the steel magnetic field modifier 94. It works to cause the magnetic poles to be drawn or sharpened.

【0021】

The steel field modifier enhances the magnetic field strength of the magnetic poles formed above it, the air or plastic is essentially neutral and does not strengthen or weaken the magnetic field, while aluminum is essentially the magnetic field. It works to eliminate or enhance or distort the magnetic field so that the magnetic field is further concentrated in the region adjacent to the neutral changer. Therefore, by appropriate selection of the current value and duration of the magnetization current pulse, the dimensions of the loop in the wire 98, the dimensions and arrangement of the magnetic field modifiers 92, 94 and 96, the material selection and the order of the magnetic field modifier arrangements. With proper selection, the dimensions, strength and location of the magnetic poles on the magnetized workpiece can be controlled very accurately.

【0022】

FIG. 9 is an illustrated representation of the magnetic pole arrangements made by the asymmetric magnetization instruments of FIGS. 7 and 8. The strong Arctic 106 is created in the center of the magnetization instrument segment shown in FIGS. 7 and 8. The somewhat weak and sharp South Pole 104 corresponds to the placement of the steel field modifier 94, with the boundary 102 of the South Pole 104 to the weak North Pole 100 occurring approximately above the aluminum field modifier 92. The magnetic flux from any one of the magnetic poles is proportional to the magnetic field strength of that pole. In a magnetized ring, the total magnetic flux from all north poles must be equal to the total magnetic flux from all south poles or into all south poles. Therefore, in the curve shown in FIG. 9, the magnetic field strength is represented by the vertical axis, and the magnetic flux is proportional to the area of the curve above or below the horizontal axis. If all the magnetic poles on the circular magnetic ring are represented in such a figure, the total area under all the North Pole would be equal to the total area covering all the South Pole.

【0023】

FIG. 10 shows an illustrated representation of the analog signal 120 and the digital signal 130 resulting from one rotation of the low resolution magnetic encoder ring 15. The analog figure 120 represents the raw output of the Hall sensor. Digital figure 130 represents the same output after adjusting the signal in the sensor circuit. These shapes represent an asymmetry that makes the distinction that allows a suitable cylinder to receive a spark signal. In this case, all the other pulses are at an angle of 2 °. Pulses 122 and 126 are 2 ° pulses, respectively, and pulses 124 and 128 are 7 ° and 12 respectively. It is a pulse of . The analog or unadjusted signal shows the sum of 16 or 8 poles for the total magnetic encoder ring. Digital figure 130 shows only 4 pulses of those generated by these 16 poles. This is done by a positive signal adjustment designed solely to recognize the magnetic field strength of the extended Arctic 115, that is, the magnetic field strength of the North Pole. Therefore, digital figure 130 only recognizes the four strong Arctic 122, 124, 126 and 128. Therefore, only four pulses are sent by the low resolution sensor circuit in the electronic controller for each revolution of the low resolution encoder ring 15. The tuning function is controlled from the rising edge of each pulse, while the identification function is determined by the angular width of each pulse.

【0024】

11 and 12 are plan views of the magnetization instrument similar to FIG. 7, but with an enlarged portion of the magnetization instrument 90 used to magnetize the low resolution magnetic encoder ring symmetrically. Shows things. These figures show the aforementioned flat meandering pattern of wire 98 along the base plate 89 and another arrangement of demagnetizers 92, 94 and 96 to achieve the desired dimensions, strength and location of the magnetic poles. Is illustrated.

【0025】

Of course, the high resolution magnetic encoder ring 10 rotates synchronously with the low resolution magnetic encoder ring 15. Since the high-resolution encoder ring 10 has 360 poles and the encoder ring 10 has two associated high-resolution magnetic field sensors 11, 720 pulses are generated for each rotation of the high-resolution encoder ring 10. To. This is even more rigorous than interpolating with a 0.5 ° resolution without interpolation.

[Simple explanation of drawings]

[Figure 1]

It is a partial elevation view of a partial cross section of a sensor device.

[Figure 2]

It is a schematic plan view of a magnetic field sensor.

[Fig. 3]

It is a schematic plan view of two magnetic coders.

[Fig. 4]

It is a schematic plan view of a magnet holding device.

[Fig. 5]

It is sectional drawing of the magnet cage seen from line 5-5 of FIG.

[Fig. 6]

It is a schematic plan view seen from the top of the upper drive hub support plate and the drive spring.

[Fig. 7]

FIG. 6 is an enlarged partial plan view of a magnetization fixture showing a single magnetization loop for the south-north-south cycle.

[Fig. 8]

An elevational view of the same magnetization fitting segment as shown in FIG. 7 is shown.

[Fig. 9]

The asymmetric magnetization generated by the magnetization fixtures of FIGS. 7 and 8 is shown.

[Fig. 10]

Shows the display of analog and digital signals detected by a magnetic field sensor from an asymmetrically magnetized encoder.

[Fig. 11]

It is a plan view of the magnetization instrument similar to FIG. 7, and shows the multiple magnetization loop for the multiple south-north-south cycle.

[Fig. 12]

It is a plan view of the magnetization instrument similar to FIG. 11, and shows the multi-magnetization instrument with magnetic field modifiers in different orders.

[Explanation of symbols]

10 High resolution magnetic coder ring 11 High resolution magnetic sensor 15 Low resolution magnetic encoder ring 16 Low resolution magnetic sensor 20 Support plate 21 Magnet holding ring 22 protruding studs 30 cases 40 drive spring 90 Magnetization instrument 94 Steel magnetic field modifier 96 Aluminum or plastic magnetic field modifier