JPH02130403A - Throttle sensor - Google Patents

Abstract

PURPOSE:To end assembling work easily and in a short time by forming a fitting part at a part where a fixed member of a throttle sensor is mounted on a throttle body at a sensor for detecting a throttle valve opening of an internal combustion engine. CONSTITUTION:A part (mounting surface) 1a intended to mount a module of a throttle body 1 is worked together when a part housing a bearing 5 of a throttle valve 2 is machined and a specified dimensional accuracy is maintained with respect to a position of holding a shaft 3 of the throttle valve 2. Also here, a fitting part 16a is formed on the surface where the module 16 is to be mounted and a groove for fitting is formed on the surface where the throttle body 1 is to be mounted corresponding to the fitting part 16a so that the module 16 is mounted in a fitting construction. Thus, a positioning of a Hall element 10 is achieved with a specified accuracy simply by pressing the module 16 on the mounting surface 1a of the throttle body 1 to tighten a screw 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sensor for detecting the opening degree of a throttle valve of an internal combustion engine, and particularly to a throttle sensor suitable for an automobile gasoline engine.

[Prior Art] In recent years, as automobiles have become more sophisticated, electronic control devices such as microcomputers have been used to control throttle valve opening, etc.

Captures various data representing the operating status of the engine,
2. Description of the Related Art A so-called electronic control type engine control device that electronically controls an engine has been widely put into practical use.

By the way, at this time, the sensor for detecting the opening of the throttle valve,
As a so-called throttle sensor, for example,
A variable resistor type sensor using contact sliding of a conductive member as disclosed in Japanese Patent Application Laid-open No. 1-40931, and
BACKGROUND ART A non-contact type throttle sensor using a magnetic detection method, as disclosed in Japanese Patent No. 6-107119, is known.

[Problems to be Solved by the Invention] Among the above-mentioned conventional technologies, the former variable resistor type sensor has a problem with its lifespan, and therefore it is necessary to unitize the entire sensor and take care to replace it.

On the other hand, the latter type of non-contact type sensor does not require such considerations regarding its lifespan, so the movable member of the sensor, which should be attached to the rotating shaft of the throttle valve, and the fixed member of the sensor, which should be attached to the throttle body, are separated. It was possible to assemble it in this way.

However, in conventional throttle sensors in which the sensor components are assembled separately, considerable positional accuracy is required for attaching the fixed member to the throttle body, which requires skill in the assembly process and increases costs. There was a problem that it was easy to upload.

An object of the present invention is to provide a throttle sensor in which a movable member and a fixed member of the sensor necessary for detecting the opening of a throttle valve are separately attached to the rotating shaft of the throttle valve, and the latter to the throttle body. When assembling the sensor, there is no need to worry about positioning the fixing member.

To provide a throttle sensor which can provide sufficient accuracy just by assembling it as is.

[Means for Solving the Problems] The above object is achieved by forming a fitting portion at the attachment portion of the fixing member of the throttle sensor to the throttle body.

[Operation] A large part of the assembling work of the throttle sensor is occupied by adjusting the mounting position of the fixed member with respect to the rotating member.

However, since this part has a fitting structure due to the presence of a fitting part, the above-mentioned positioning is automatically achieved simply by attaching the fixing member to the throttle body, making the assembly process easy and quick. can be terminated.

[Example] The throttle sensor according to the present invention will be described below.

This will be explained in detail with reference to the illustrated embodiment.

FIG. 1 shows an embodiment of the present invention, in which 1 is a throttle body, and a throttle valve 2 is fixed to a throttle valve shaft 3 by a fixing screw 4. In FIG. Further, the throttle valve shaft 3 rotates in response to the operation of an accelerator pedal (not shown), and is held by the throttle body 1 via a bearing 5. Reference numeral 6 denotes a magnetic field source holding member made of metal, such as iron or aluminum, and is fixed to one end of the throttle valve shaft 3 by a coupling method such as press fitting.

7 is a magnetic field generation source joined to the magnetic field generation source holding member 6, and as shown in FIG. 2, one has an arc shape in this embodiment;
It consists of a permanent magnet 8 and a yoke 9 which has the same contour shape as the permanent magnet 8 and is joined to it. This yoke 9 is made of ferromagnetic metal and has a permanent magnet 8.
is magnetized in the height direction (S pole, N pole) so that the magnetic flux density B0 on the surface is uniform along its length direction, and the surface of the yoke 9 on the Hall element 10 (described later) side is exposed to the magnetic field. Source 7
The magnetic pole face 7a is opposed to the Hall element 10. Then, the magnetic field source holding member 6 and the magnetic field source 7
The throttle valve 2 has a structure that rotates together with the throttle valve shaft 3, and the throttle valve 2 as a whole constitutes a rotating member of the throttle sensor. Further, the yoke 9 is formed in a shape whose height changes linearly along the rotational displacement θ, so that the magnetic pole surface 7a has a slope shape with respect to the rotational displacement θ, and the magnetic flux density B passing through the Hall element 10 is increased. Change.

As is well known, the Hall element 1o is a four-terminal magnetic flux detection element, and as shown in FIG.
and earth GND are connected, and as a result, Hall voltage signals U and U0 corresponding to the magnetic flux density B are output from the other pair of terminals, and this signal U is output.

Uo is connected to the input portions of operational amplifiers OPI and OP2 of the amplifier circuit 11.

The amplifier circuit 11 is set so that R4, R5>R3, and as a result, the internal resistance of the Hall element 10 (not shown)
If , is ignored, the output voltage Vo will be expressed as shown in equation (1) according to Kirchhoff's law and Ohm's law.

Here, the Hall voltage vlI is given by V, l = U0. Furthermore, as is clear from equation (1), if the resistance R1 is set to a fixed value, the Hall voltage v
The amplification gain (gain) of the output voltage va with respect to H is defined. On the other hand, the Hall element 10 has a magnetic flux density B
If B=O, then VR=O, that is, v0=0, but in reality, even when B=O, there is an unbalanced voltage vI4°=U nee U in the Hall element 10. (not shown),
As is clear from equation (1), the output voltage V. offset voltage V. F (not shown) occurs (Vo=Vop:
B = O('l Toki) Also, this offset voltage V. It is known that F varies depending on the Hall element.

Therefore, when B=O, ■. In order to make =Vop=O, the zero point (offset) of vo is defined by adjusting the resistors R4 and R (not shown).

Further, the output signal V from the amplifier circuit 11 when the power supply Vc applied to the Hall element 10 is constant.

As shown in FIG. 4, changes linearly in proportion to the magnetic flux density.

On the other hand, since the magnetic pole surface 7a of the magnetic field generating source 7 is sloped with respect to the rotational displacement θ of the throttle valve shaft 3, as described above, the relationship between θ and B is as shown in FIG.

Therefore, the output voltage v0 for the rotational displacement θ of the throttle valve shaft 3
The relationship is as shown in FIG. 6, and since vo changes linearly with respect to θ, the rotational displacement θ of the throttle valve shaft 3 can be detected without contact.

These Hall elements 10. The amplifier circuit 11 is disposed on a substrate 12 made of, for example, ceramic, and constitutes a fixing member of the throttle sensor as a whole, and is connected to a connector 14 via a lead frame 13, and outputs an output signal v0, a power supply VC, and a ground GND to the outside. , or allow external relaying.

Further, a magnetic shield cover 15 made of a ferromagnetic metal body is provided for magnetically shielding the magnetic field generation g7 and the Hall element 10 from the outside. The module 16 is integrally molded with plastic material.

Then, as shown in FIG. 7, this module 16 is
It is removably attached to the throttle body 1 using body attachment screws 17. Note that the module 16 and the throttle body 1 are sealed by an O-ring 18.

At this time, the part (mounting surface) la of the throttle body 1 to which the module 16 is attached is machined together with the part that accommodates the bearing 5 of the throttle valve 2, and the shaft 3 of the throttle valve 2 The module 16 is fitted onto the mounting surface of the module 16 so that a predetermined dimensional accuracy is maintained with respect to the holding position, and the module 16 is fitted onto the throttle body 1 in a fitting structure. Part 1
6a, and correspondingly, a fitting groove is formed on the mounting surface 1a of the throttle body 1. Of course, this fitting groove is also machined together with the accommodating portion of the bearing 5 to provide a predetermined dimensional accuracy.

Therefore, simply by pressing the module 16 against the mounting surface 1a of the throttle body 1 and tightening the screw 17, the Hall element 10 can be positioned with a predetermined accuracy.

In this way, after the module 16 is attached to the throttle body 1, an opening 19 is provided in order to make it possible to adjust the gain by the amplifier circuit 11 and the above-mentioned zero point.
1 can be adjusted by arbitrarily replacing the resistors R, , R4, and R.

After the adjustment is completed, the opening 19 is sealed with silicone resin 20 or the like.

In the above embodiment, the magnetic field generation source 7 was composed of the permanent magnet 8 and the yoke 9, but as shown in FIG. The height may be sloped with respect to the displacement θ.

Further, in the above embodiment, the Hall element 1o, the amplifier circuit 1
1 on which the substrate 12.1 is placed. The connector 14, magnetic shield cover 15, and module 16 are integrally formed, as shown in FIGS. 9 and 10.

After the board 12, lead frame 13, and connector 14 are integrally formed into a module 16 and fixed to the throttle body 1 with body mounting screws 17, resistors R, , R, , R are provided for adjusting the amplification gain and zero point.

Install. A magnetic shield cover 15 made of a single ferromagnetic metal may be fixed to the module 16 with second mounting screws 40 so as to surround the Hall element 10 and the magnetic field generation source 7.

Furthermore, in the above embodiment, the magnetic field generation source 7 was arranged between the throttle body 1 and the Hall element 10, but as shown in FIG. A configuration in which the elements 10 are arranged may also be used. In this case too.

After attaching the resistors R, , R4, R, the magnetic shield cover 15 is fixed to the module 16 with the second mounting screw 40 so as to surround the Hall element 10 and the magnetic field generation source 7.

In each of the above-mentioned embodiments, the resistors R2, R4, and R for amplification gain and zero point adjustment were arranged on the substrate 12, but the first
As shown in FIG. 2, a fixing space 51 may be provided in the connector 14 from the substrate 12 via the second lead frame, and the resistors R2, R4 and R6 may be disposed therein.

In all of the above embodiments of the present invention, by combining a permanent magnet with a Hall element, the opening degree of the throttle valve can be detected without contact, and long life and high reliability can be easily ensured. can.

Further, since the Hall element, the amplifier circuit board, the connector, the magnetic shield, etc. are integrated as a module, the configuration can be simplified and the device can be sufficiently miniaturized.

In addition, in the above embodiment, a magnetic detection method using a Hall element is adopted in order to detect the angle without contact.
The present invention is not limited to this and can be implemented.

Even optical methods and magnetic detection methods do not rely on Hall elements,
It goes without saying that the present invention may be implemented using other magnetic detection elements, or even may be implemented using a variable resistor system.

[Effects of the Invention] As explained above, according to the present invention, extra care for positioning is not required when assembling the sensor.
By making full use of the characteristics of a non-contact type sensor, it is possible to easily provide a throttle sensor with sufficient accuracy at low cost, in which a movable member and a fixed member of the sensor are assembled separately.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the throttle sensor according to the present invention, FIG. 2 is a partially enlarged view thereof, FIG. 3 is a circuit diagram for detecting an angle signal, FIGS. 4 and 5, and FIG. Figure 6 is a characteristic diagram for explaining the operation, Figure 7 is a side view of Figure 1, and Figure 8 is a
A partially enlarged view showing another embodiment of the present invention, FIGS. 9 and 10 are a sectional view and a side view showing still another embodiment of the present invention, and FIGS. 11 and 12 are views of the present invention. FIG. 7 is a sectional view and a side view showing still another embodiment of the invention. 1... Throttle body, 1a... Mounting surface, 2... Throttle valve, 3... Throttle valve shaft, 4... Fixed screw, 5... Bearing, 6... Magnetic field source holding member, 7...
Magnetic field source, 8...Permanent magnet, 9...
Yoke, 10...Hall element, 11...
- Amplifier circuit, 12... Board, 16... Module, 16a... Fitting part. 2nd cause Figure 3 Figure 1 Niss throttle body 9: Yoke la: Mounting surface IO: Hole fA+ 2: Thread valve 12: Base 4 anti-3-diaphragm #Higashiyama I4: Co thread 9 7: 凰 M -A must-see 1. 16: Recessed nail 7a: , 5a living surface 16a: Fitting part 8: Long sleeve 4 Figure 5 Figure 6 Plan O

Claims (1)

[Scope of Claims] 1. In a throttle sensor that detects the throttle valve opening degree based on the relative position of a movable member attached to the rotating shaft of the throttle valve and a fixed member attached to the throttle body, the fixed member A throttle sensor characterized in that a fitting portion is provided at the attachment portion to the throttle body, and the fitting portion provides positioning of the fixed member with respect to the movable member. 2. The invention according to claim 1, wherein the fixing member is modularized including a detection circuit, and the modularized member is configured to be detachable from the throttle body through the fitting portion. Throttle sensor. 3. The throttle sensor according to claim 2, wherein the relative position detection between the movable member and the fixed member is performed in a non-contact manner by a magnetic detection method. 4. The throttle sensor according to claim 3, wherein the modular member includes a magnetic shielding member. 5. The throttle sensor according to claim 4, wherein the magnetic shielding member is constituted by a shielding plate made of a magnetic material embedded in a substrate portion of the modularized member. 6. The throttle sensor according to claim 4, wherein the magnetic shielding member is a cover member made of a magnetic material that covers at least a portion of the modular member. 7. In the invention according to claim 3, the movable member is composed of a permanent magnet and a magnetic yoke member for changing the magnetic field generated by the permanent magnet in the rotating direction, and the fixed member is composed of a magnetic detection element. A throttle sensor characterized by: