WO2001071288A1 - Torsional quantity measuring device - Google Patents

Abstract

The torsional quantity measuring device is such that for the purpose of providing a torque measuring device that is simple in construction and small in size and can be produced at low cost, and to achieve this purpose, the torsional quantity measuring device has an inlet-side rotor (2) and an outlet-side rotor (4) that are circumferentially turnably disposed, and detects the relative torsional quantities of these inlet-side and outlet-side rotors (2, 4), wherein the device comprises an inlet-side stator (1) disposed at a position circumferentially opposed to the inlet-side rotor (2) with a predetermined spacing therebetween, an outlet-side stator (3) disposed at a position circumferentially opposed to the outlet-side rotor (4) with a predetermined spacing therebetween, the inlet-side and outlet-side stators (1, 3) respectively having exciting windings and output windings (5, 6), the output winding of the inlet-side stator (1) and the output winding of the outlet-side stator (3) being interconnected.

Description

Technical field of torsion measuring device

 According to the present invention, an input shaft and an output shaft are rotated while twisting a torsion par by rotating an input shaft like a power steering device for an automobile. The present invention relates to a torsion amount measuring device for calculating and measuring a torque by detecting a relative rotation amount of the torsion force via a resolver. '' Background technology

 In the conventional apparatus shown in FIGS. 7 to 10, one end of the torsion bar 101 is fixed to an input shaft (not shown), and the other end is fixed to an output shaft (not shown). When the handle is rotated to rotate the input shaft, the input shaft and the output shaft rotate while twisting the torsion bar 101. The input torque can be detected by detecting the torsion amount of the torsion par 101 at this time, that is, the relative rotation amount of both shafts. As described above, the resolver mechanism detects the amount of relative rotation between the two shafts. The resolver mechanism will be specifically described below.

The input side cylindrical rotor 102 is fixed to the input shaft side of the torsion bar 101, and the output side cylindrical rotor 103 is fixed to the output shaft side. The housing 104 surrounds both the rotors 102 and 103. As shown in FIG. 8, an annular first yoke 105 is provided on the inner periphery of the housing 104, and a first coil 106 is provided in the first yoke 105. . An annular second yoke 107 facing the first yoke 105 is fixed to the outer periphery of the input-side cylindrical rotor 102, and a second coil 108 is provided therein. I have. Then, the first yoke 105 and the first coil 106 and the second yoke 107 and the second coil The magnetic circuit (rotary transformer) is composed of the two coils 108.

 Further, a third yoke 109 is fixed to the input side cylindrical rotor 102 on the circumference thereof. Around the third yoke 109, a third coil 110 composed of two types of coils with phases shifted by 90 ° is wound, and the third coil 110 is attached to the second coil 110. Connected to 108. On the other hand, on the inner periphery of the housing 104, a fourth yoke 111 and a fourth coil 112 facing the third yoke 109 and the third coil 110 are provided. The fourth coil 112 is also composed of two types of coils whose phases are shifted by 90 °, like the third coil 110. These components constitute an input-side resolver mechanism R 1. In the drawing, reference numeral 113 denotes a lead wire connected to the first coil 106, and 114 denotes a lead wire connected to the fourth coil 112, both of which are outside the housing 104. I'm pulling out.

 The input-side resolver mechanism R1 as described above is provided between the input-side cylindrical rotor 102 and the housing 104, but between the output-side cylindrical rotor 103 and the housing 104. Also, an output-side resolver mechanism R2 exactly the same as the input side is provided. FIG. 9 is a circuit diagram showing the above resolver mechanism.

 When the torsion bar 101 is twisted, when the AC voltage ER1 is applied to the first coil 106, a magnetic flux is generated in the first yoke 105 and the second yoke 107 in accordance with the voltage. However, an AC voltage is induced in the second coil 108 according to the magnetic flux density at that time. Since the second coil 108 is connected to the third coil 110, an AC voltage is also generated in the third coil 110. However, since the third coil 110 is composed of two types of coils whose phases are shifted by 90 °, the generated voltages are also shifted by 90 ° in phase. The AC voltage generated in the third coil 110 induces an AC voltage in the fourth coil 112, and the AC voltage of the fourth coil 112 is transferred from the lead wire 114 to the housing 110. 4 It is taken out.

The output voltages ES1 and ES2 taken out of the housing 104 are as follows. is there.

 ESl = kERl X cos 0 1 ES2 = kERl X sin 0 1

 Note that k indicates a transformation ratio. The output voltage characteristics at this time are as shown in FIG. 0 1 can be calculated from the above two equations. This angle Θ1 is the rotation angle of the input-side cylindrical rotor 2. Θ1 calculated in this manner is stored in a computer (not shown) via a resolver digital converter (hereinafter, an R / D converter). Similarly, from the output-side resolver mechanism R2, the rotation angle 検 出 2 of the output-side cylindrical rotor 2 is detected and input to the computer. Then, the computer calculates the relative angle Δ0 between the input side and the output side as Aθ = θ1−102, and calculates the relative angle Δ0 which is the torsion angle of the torsion par 1 and the rigidity of the torsion bar 1. And calculate the torque.

 The conventional device described above requires a resolver mechanism and an RZD converter on both the input and output sides. Then, using the signals obtained from the two sets of resolver mechanisms to calculate and detect the torque, there is a problem that the device becomes expensive accordingly. In addition, as described above, an arithmetic circuit for calculating Δ0 and a wiring structure for routing them are required, so that the space for incorporating them must be increased, and the entire device becomes larger and more expensive. There was a problem of becoming. Disclosure of the invention

 An object of the present invention is to provide a torque measuring device which has a simple structure and can be reduced in size and cost.

 The above object is achieved by the following configurations.

(1) An input-side rotor (2) and an output-side rotor (4) arranged rotatably in the circumferential direction, and a relative screw between the input-side rotor (2) and the output-side rotor (4) is provided. A torsion measuring device for detecting the amount of distortion, An input stator (1) is provided at a predetermined interval at a position facing the input rotor (· 2) in the circumferential direction,

 An output stator (3) is provided at a predetermined interval at a position facing the output rotor (4) in the circumferential direction,

 The input-side stator (1) and the output-side stator (3) have an excitation winding and an output winding (5, 6), respectively, and the output winding and the output side of the bracket-side input stator (1) are provided. A torsion measuring device in which the output winding of the stator (3) is interconnected.

 (2) The torsion amount measuring device according to (1), wherein an excitation signal is input to an excitation winding of the input-side stator (1), and an output signal is obtained from the excitation winding of the output-side stator (3).

 (3) The output winding of the input-side stator (1) and the output winding of the output-side stator (3) have a multi-phase winding,

 The torsion measuring device according to (1) or (2), wherein the in-phase windings are connected to each other.

 (4) The torsion amount measuring device according to any one of (1) to (3), wherein the output signal is synchronously rectified to be a signal representing the amount of torsion.

 (5) At least between the input-side stator (1) and the output-side stator (3), there is provided a magnetic shielding means (9).

BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a cross-sectional view of the torsion measuring apparatus of the present invention.

 FIG. 2 is a circuit diagram of the excitation winding and the output winding of FIG.

 FIG. 3 is a cross-sectional view of a main part of the example.

 FIG. 4 is a circuit diagram illustrating an example of the synchronous rectifier circuit.

FIG. 5 is an output voltage characteristic diagram of the circuit of FIG. FIG. 6 is a cross-sectional view showing another configuration example of the torsion amount measuring device.

 FIG. 7 is a schematic diagram of a conventional device.

 FIG. 8 is a cross-sectional view of the resolver mechanism.

 FIG. 9 is a circuit diagram.

 FIG. 10 is an output voltage characteristic diagram. BEST MODE FOR CARRYING OUT THE INVENTION

 The torsion measuring apparatus of the present invention has an input rotor 2 and an output rotor 4 that are rotatably arranged in the circumferential direction on the same axis as shown in FIG. 1, for example. A torsion amount measuring device for detecting a relative amount of torsion between the input side rotor 4 and the output side rotor 4, comprising an input side stator 1 at a predetermined interval at a position facing the input side rotor 2 in a circumferential direction; An output-side stator 3 is provided at a predetermined interval at a position facing the output-side rotor 4 in the circumferential direction, and the input-side stator 1 and the output-side stator 3 are each provided with an excitation winding and an output winding 5. , 6, wherein the output winding of the input side stator 1 and the output winding of the output side stator 3 are connected to each other. Then, an excitation signal is input to the excitation winding of the input-side stator, and an output signal is obtained from the excitation winding of the output-side stator. Alternatively, the reverse is also true.

Preferably, the output winding of the input-side stator and the output winding of the output-side stator have windings of a plurality of phases, and the windings of the same phase are connected to each other. Referring to FIG. 1 in more detail, a resolver as a torsion amount measuring device has an input-side rotor 2 and an output-side rotor 4 that are rotatably arranged on the same axis in a circumferential direction. A rotating body (not shown) for detecting the amount of twist is connected to the input-side rotor 2 and the output-side rotor 4. This rotating body is not particularly limited as long as one has a displacement amount (rotation amount) relatively different from the other, but preferably, the difference between the relative displacement amounts is ± Within 45 °, especially ± 0 ~ 22.5 ° is preferred. New

 The rotors 2 and 4 are deformed cylindrical or disc-shaped magnetic bodies, and the gap between the outer surface thereof and the magnetic poles of the stators 1 and 3 is changed by the rotation operation, and the rotors 2 and 4 are rotated by the excitation winding and the output winding. It is formed so that an output signal corresponding to the displacement amount can be obtained. This shape may be a disk-shaped or cylindrical rotating body whose center axis deviates from the center axis of the stator, but as will be described later, in order to remove harmonic distortion, the shape is determined by a predetermined number of poles. It is preferable that the outer periphery has a shape having a projection with a special curve.

 The preferred shapes of the rotors 2 and 4 will be described. The shape of the rotors 2 and 4 is preferably a force that can use a technique for determining the shape of the rotor of a normal barrier bunreller-lattans type resolver.Preferably, as described in Japanese Patent No. 2698013 Use the method that is used.

 The rotors 2 and 4 are made of a magnetic material with N salient poles and have no windings.The rotor is driven by the magnetomotive force generated by the current of the exciting flute and the fluctuation of the gap permeance caused by the salient poles. When moving 1 ZN around the entire circumference, the spatial position of the peak value of the magnetic flux density uses the movement 1 ZN around the entire circumference.

 The induced voltage to the output winding due to this magnetic flux density is as follows: When the excitation winding is single-phase and the output winding is two-phase or three-phase, the movement of 1 / N of the entire circumference of the rotor is one cycle. If the excitation winding is two-phase and the output winding is single-phase, the amplitude will be one cycle when the rotor moves 1 / N of the entire circumference. (Electrical angle 2π) The sine wave voltage changes. The relationship between these voltages and the rotor position is the same as the resolver or synchro currently used.

In this method, it is important to minimize the harmonic components contained in the induced voltage of the output winding, which cause errors. In the present invention, the value varies according to the rotor position 6 ₂ Gyappupa Miansu coefficient due New salient poles is proportional to c 0 s (Ν 0) and Do Ri, salient pole shape as harmonic component is extremely small with respect to this By doing This can be achieved.

 An input stator 1 is provided at a position facing the input rotor 2 in the circumferential direction at a predetermined interval, and an input side stator is provided at a position facing the output rotor 4 in the circumferential direction at a predetermined interval. It has a stator 3. These stators 1 and 3 are fixed to a resolver case 7.

 Each of the stators 1 and 3 is a hollow annular magnetic body, has a plurality of magnetic poles protruding in the axial center direction, and has a configuration in which a slot for winding is wound between these magnetic poles. .

 An excitation winding and output windings 5 and 6 are wound around the magnetic poles of such a stator. The excitation winding is a winding for generating a magnetic field, and the output winding is a winding for extracting an excitation voltage generated by the excitation winding and excited by a magnetic field that is changed by rotational movement of the motor. It is preferable that the output winding has a distributed winding so that the generated induced voltage distribution becomes a sinusoidal distribution.

 Further, as shown in FIG. 6, for example, it is preferable to have magnetic shielding means 9 so that the output side output winding is not directly electromagnetically induced by the excitation signal of the input side stator. The magnetic shielding means is not particularly limited as long as it can shield the magnetism. For example, a shielding plate made of a magnetic material may be provided. The other configurations in FIG. 6 are the same as those in FIG. 1, and the same components are denoted by the same reference numerals and description thereof will be omitted.

 Thus, the input-side rotor 2 and the input-side stator 1 form an input-side resonator, and the output-side rotor 4 and the output-side stator 3 form an output-side resolver. With these two resolvers, the amount of displacement on the input and output sides can be detected as electrical signals.

In the present invention, the output winding of the input-side stator and the output winding of the output-side stator are connected to each other. Specifically, for example, as shown in FIG. The magnetic winding 5a and the output windings 5b and 5c are wound, and the exciting winding 6a and the output windings 6b and 6c are wound on the output side stator 3.

 In this example, of the two-phase output windings, the terminals S 1 and S 2 of the input-side first-phase output winding 5 b and the terminal S 1 of the output-side first-phase output winding 6 b 1 and S12 are connected respectively. Similarly, the terminals S3 and S4 of the output winding 5c of the second phase on the input side are connected to the terminals S13 and S14 of the output winding 6c of the second phase on the output side. By connecting the output windings to each other in this way, when the input signal ERI is applied between the terminals R 1 and R 2 of the excitation winding 5 a on the input side, the terminal of the excitation winding 6 a on the output side is applied. An output signal ERo expressed by the following equation appears between R11 and R12.

 That is, the input signal of the following formula

 E R I = E s i η ω t

 Is applied between terminals S 1 and S 2,

 Depending on the displacement φ on the input side, between the terminals S 1-2 and S 3 _ 4 of the output windings 5 b and 5 c,

 E S 1— 2 = K i E s i η ω t · cos (X · φ)

 ES 3-4 = K i E s ΐ ηω ΐ-s in (Χ

 Appears. And this is applied between the terminals SI 1-12 and SI 3-14 of the output windings 6 b and 6 c, so that the output is connected between the terminals R 11 and R 12 of the exciting winding 6 a on the output side. Output voltage according to the amount of displacement

 ERo = Ko s η ηω ΐ-s i nX (φ- θ)

 (Κ i, Κο: Transformation ratio, X: Double shaft angle (X = l ~ 8, especially 2 ~ 8))

 Is obtained.

Since the obtained output waveform is superimposed with the excitation signal E si η ωt, the superimposed excitation signal component is removed by a detection circuit, rectifier circuit, etc., to reduce the displacement angle, that is, the amount of twist. The corresponding signal, K si nX (φ ~ θ) CK: Transformation ratio (coefficient)]

Is obtained.

 In the present invention, it is preferable to extract and use only a linear region from the obtained signal. That is, the torsion amount measuring apparatus of the present invention does not need to measure 360 ° full angle of the rotation amount, and the displacement angle is within ± 20 °, preferably within 15 ° of soil for normal steering. It is enough to be able to measure. Therefore, the obtained output signal, sin X (φ-θ)

If the linear region is within the above measurement angle, the displacement (torsion) can be replaced with a linear signal.

Example

 Next, a preferred embodiment of the present invention will be described with reference to the drawings. The torsion amount measuring device shown in FIG. 3 shows an example of measuring the torsion amount of a torsion bar in a power steering of a vehicle.

 In the figure, an input shaft and an output shaft of a torsion bar 13 are connected to an input-side rotor 2 and an output-side rotor 4, respectively. Other configurations are the same as those of the measuring apparatus shown in FIG. 1, and the same components are denoted by the same reference numerals and description thereof will be omitted. The two resolvers are housed in the housing case 8. In this example, the shaft double angle X was set to 4.

 In the torsion measuring device having such a configuration, when the excitation input voltage Esinct is applied to the excitation inputs R1 and R2 on the input side, a signal corresponding to the torsion angle is obtained.

 ER o = K o s i η ω i · s in 4, φ— Θ)

Is output.

The obtained output signal is a single output, and the output signal line can be extracted by a pair of signal lines corresponding to R11-R12. As a result, the number of signal lines, which previously required eight, is reduced to less than half, and the reliability is more than doubled. Next, the obtained output signal ERo was applied to the input terminal IN1 of the synchronous rectifier circuit as shown in FIG. This synchronous rectifier circuit includes an amplifier circuit including two operational amplifiers OP1 and OP2 and resistors R1 to R5, and an analog switch SW that switches the output of the amplifier circuit in a time-division manner. Then, high-frequency components are removed from the output of the analog switch SW by a low-pass filter including an operational amplifier OP3, a capacitor C1, and resistors R7 and R8. The excitation signal E si ηω t input to the other input terminal I N2 is converted into a rectangular signal by a comparator circuit composed of the comparator OP 4 and the resistors R 6, 9, and 10, and the analog switch SW is turned on. Drive.

'This allows the signal input to input terminal I N 1

Ko s ι ηω ΐ · s i n4 (— θ)

Therefore, the excitation signal component Ε s i ηω t given to the other input terminal I Ν2 is removed by an analog switch synchronized with this signal, and the high frequency component is further removed.

K s i n 4 (φ— θ)

Is obtained. Fig. 5 shows the obtained output signal.

 The region indicated by R in the figure is a linear region, and the region soil r is preferably within 22.5 °, more preferably within ± 20 °. When the torsion amount measuring device of the present invention is used for ordinary steering control, displacement angle measurement within ± 10 ° is sufficient. Therefore, by using the signals in the linear region, a synchronous rectifier circuit combining an inexpensive operational amplifier and a comparator can obtain a linear signal according to the displacement amount without using an RD converter that performs AZD conversion. It can be seen that the number of wires can be reduced to 1/4.

In other words, there is no need to calculate Δ0 from the two signal waveforms, there is no need for an arithmetic circuit, and the number of wirings is reduced. It can be significantly reduced. In addition, the fact that the number of components attached to the resolver can be reduced means that the entire device can be reduced in size, can be used in a place where the installation space is small, and the cost can be reduced as a whole. In addition, the number of components, particularly the number of wirings, is reduced, so that reliability is improved. Therefore, the manufacture of the resolver mechanism becomes extremely simple. The invention's effect

 As described above, according to the torsion amount measuring device of the present invention, it is possible to provide a torque measuring device that has a simple structure and can be reduced in size and cost.

Claims

The scope of the claims 1. An input-side rotor (2) and an output-side rotor (4) arranged rotatably in the circumferential direction. The relative twist between the input-side rotor (2) and the output-side rotor (4). A torsion measuring device for detecting the amount,  An input stator (1) is provided at a predetermined interval at a position facing the input rotor (2) in the circumferential direction,  An output stator (3) is provided at a predetermined interval at a position facing the output rotor (4) in the circumferential direction,  The input-side stator (1) and the output-side stator (3) have an exciting winding and an output winding (5, 6), respectively, and the output winding and the output side of the bracket-side input stator (1) are provided. A torsion measuring device in which the output winding of the stator (3) is connected to each other.  2. The torsion measurement according to claim 1, wherein an excitation signal is input to an excitation winding of the input-side stator (1), and an output signal is obtained from an excitation winding of the output-side stator (3). 3. The output winding of the input stator (1) and the output winding of the output stator (3) have a multi-phase winding,  3. The torsion measuring device according to claim 1, wherein windings having the same phase are connected to each other.  4. The torsion amount measuring device according to any one of claims 1 to 3, wherein the output signal is synchronously rectified to be a signal representing a torsion amount.  5. The torsion measurement according to any one of claims 1 to 4, further comprising a magnetic shielding means (9) between at least the input side stator (1) and the output side stator (3). apparatus.