JPH0579931A - Torque detecting device - Google Patents

Abstract

PURPOSE:To provide a torque detecting device capable of detecting the correct torque synchronous with the rotary position of the power shaft of a power generating engine. CONSTITUTION:The torque applied to a crank shaft 2 transmitting the power generated by an engine 1 is detected. The pulse signal of a crank angle detecting sensor 10 detecting the rotary position of the crank shaft 2 is extracted by a rotary position detecting means 20 as the rotary position signal S1. A magnetic recording medium 3 is fixed on the periphery of the crank shaft 2, and a signal recording means 30 records the magnetic pattern synchronous with the rotary position signal S1 on the magnetic recording medium 3 with a magnetic head 40. The magnetic pattern recorded on the magnetic recording medium 3 is regenerated by a signal regenerating means 50 as the regeneration signal S2. A torque arithmetic means 60 detects the torque applied to the crank shaft 2 based on the phase difference between the rotary position signal S1 and the regeneration signal S2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a torque detecting device, and more particularly,
The present invention relates to a torque detection device that detects a torque acting on a power shaft of an internal combustion engine or an electric motor based on the amount of twist of the power shaft.

[0002]

2. Description of the Related Art In a power generating engine such as an internal combustion engine or an electric motor, demand for a torque detecting device for detecting a torque acting on a power shaft tends to increase more and more. For example, in an automobile, detection of torque at the crankshaft is very important for optimal engine control.

When the accelerator is suddenly depressed during operation, the torque of the engine suddenly increases and the drive system is twisted.
This twist causes the low frequency transient vibration of the drive system to occur. Such unpleasant vibration is called a hiccup phenomenon. Conventionally, in order to prevent this hiccup phenomenon, the shaft diameter of the drive system has been increased and tires and suspensions have been improved, but such a method reduces noise (crowded noise), manufacturing cost, fuel consumption. There was a problem in terms of.

As an effective solution to this hiccup phenomenon, for example, Japanese Laid-Open Patent Publication No. 60-26131 discloses that the torque of a power shaft is detected and a reverse torque is generated to cancel the torque. A method of controlling an engine is disclosed in. Here, to detect the torque,
A torque detection device is used that calculates torque based on the torsion angle of the power shaft.

[0005]

As has been described above, the conventionally proposed torque detecting device obtains the twist angle of the power shaft and calculates the torque based on this twist angle. More specifically, a pattern having a predetermined pitch in the circumferential direction is recorded in each of two places with a predetermined interval along the power axis, and the two patterns are read out, and the phase difference between the two read signals is used. This is to find the twist angle of the power shaft. However, the torque detection device based on such a principle cannot obtain a torque value that is continuous in time. This is because the phase difference between the two signals cannot be obtained without using the rising time or falling time of the signals as a reference. Therefore, the torque value in the above-described torque detection device is a value that is detected only when the signal rises or falls and is intermittently detected at predetermined time intervals.

By the way, when controlling the engine of an automobile, a crank angle detection sensor for detecting the rotational position of the crankshaft is provided, and the ignition timing control and the empty timing control are performed each time the crank angle detection sensor generates a predetermined output. Calculation for fuel ratio control is performed. Therefore, in order to use the detected torque value for the engine control of the automobile, it is necessary to obtain the torque value at a timing synchronized with the output of the crank angle detection sensor. For example, if the crankshaft is 1 °
Consider a case in which one pulse signal is output from the crank angle detection sensor each time the engine rotates, and calculations for ignition timing control and air-fuel ratio control are performed when each pulse signal is output. In this case, if the torque value is used for the calculation, the torque detection device must output the torque value every time the crankshaft rotates 1 °. However, the conventionally proposed torque detection device outputs the torque value irrespective of the rotation of the crankshaft, so the torque value output from the torque detection device and the rotation of the crankshaft are synchronized. Had to take. Therefore, there has been a problem in that the detected torque value used for the calculation is delayed or an additional means for synchronizing is required.

The above-mentioned problem is not limited to an internal combustion engine such as an engine, but is similarly posed to a general power generation engine including an electric motor. For example, in a machine tool that performs cutting, it is necessary to perform optimal cutting control in consideration of processing materials and tools in order to improve productivity and quality. Therefore, control must be performed so that the torque generated on the power shaft to which the electric motor is connected is optimized. Since such control is performed in synchronization with the rotary encoder that detects the rotational position of the power shaft, it is necessary to synchronize the torque value output from the torque detection device with the output of the rotary encoder. Furthermore, when attaching the rotary loader and the torque detection device to the power shaft,
Since an installation error related to the rotational position is unavoidable, it is difficult to ensure accurate synchronization between the two. Even if the mounting is performed in a state where highly accurate synchronization can be secured, an error due to a change with time will occur in the future.

Therefore, an object of the present invention is to provide a torque detecting device capable of performing accurate torque detection in synchronization with the rotational position of a power shaft of a power generating engine.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a torque detecting device for detecting a torque acting on a power shaft of a power generating engine, and a rotational position detecting means for detecting a rotational position of the power shaft, and a torque detecting device fixed on the power shaft. The magnetic recording medium, the magnetic head for recording and reproducing a predetermined signal on the magnetic recording medium, and the predetermined magnetic information based on the detection signal of the rotational position detecting means are recorded on the magnetic recording medium using the magnetic head. Signal reproducing means for reproducing magnetic information recorded on a magnetic recording medium using a magnetic head, a phase difference between the detection signal of the rotational position detecting means and the reproduction signal of the signal reproducing means. And a torque calculation means for calculating a torque acting on the power shaft based on the detected phase difference.

[0010]

[Operation] With the torque detection device according to the present invention, two types of information indicating the rotational position of the power shaft of the power generation engine are obtained. The first information is information obtained from the rotational position detecting means. This rotational position detecting means can use the existing equipment for the power generation engine as it is. For example, in the case of an automobile engine, the crank angle detection sensor provided to detect the rotational position of the crankshaft may be used as it is. In the case of a machine tool using an electric motor, the rotational position of the power shaft may be changed. The rotary encoder provided for detection may be used as it is. Second
The information of is information obtained from the magnetic recording medium. A feature of the present invention is that rotational position information based on the first information obtained from the rotational position detecting means is recorded in advance on this magnetic recording medium. In other words, the rotational position information recorded on the magnetic recording medium is information synchronized with the first information obtained from the rotational position detecting means. The torque value to be detected is obtained by obtaining the phase difference between the second information read from this magnetic recording medium and the first information obtained from the rotational position detecting means. That is, the torque acting on the power shaft is detected based on the twist angle of the power shaft. As described above, since the second information is synchronized with the first information, the torque detection value is also obtained in synchronization with the first information (that is, the rotational position of the power shaft). Further, since the second information is recorded on the magnetic recording medium, it can be rewritten at any time, and errors due to mounting and errors due to aging can be rewritten at any time by rewriting the second information. Can be offset.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. FIG. 1 is a block diagram showing an embodiment in which the torque detection device according to the present invention is applied to an internal combustion engine (an automobile engine in this example). The power generated by the engine 1 is
It is transmitted from a crankshaft 2 as a power shaft to a wheel (connected to the right side in the drawing) via a transmission and a drive shaft. A crank angle detection sensor 10 is provided to detect the rotational position of the crankshaft 2. The crank angle detection sensor 10 is an existing device for obtaining rotational position information necessary for controlling the ignition timing of the engine 1 and the like, and is not a device specially provided for the torque detection device according to the present invention. .. The signal detected by the crank angle detection sensor 10 is the rotational position detection means 2
Given to 0.

FIG. 2 shows an example of the crank angle detecting sensor 10. The example shown here is for optically detecting the rotational position of the crankshaft 2, and is composed of a light emitting diode 11, a light receiving diode 12, and a signal disk plate 13 installed between them. .. The center portion of the signal disc plate 13 is fixed to the crankshaft 2 and rotates with the rotation of the crankshaft 2. In this example, slits are formed on the circumference of the signal disc plate 13 at every crank angle of 1 °. When the beam from the light emitting diode 11 shown by the broken line in the figure passes through this slit, the light receiving diode 12 receives this beam. The light receiving diode 12 generates a pulse signal each time the beam is received. Therefore, a pulse is input to the rotational position detecting means 20 every time the crankshaft 2 rotates by 1 °. The crank angle detection sensor 1 shown in FIG.
0 is shown as an example, and in addition to this, a sensor of magnetic induction type or the like is used. In short, the crank angle detection sensor 10 has a rotational position of the crankshaft 2 (a physical quantity equivalent to the rotational speed. For example, 7
The rotation position of 60 ° corresponds to two rotations. ), Any device may be used as long as it can detect the above), and as described above, the existing device for each engine control system may be used as it is.

The description will be continued again with reference to FIG. The rotational position detection means 20 is a circuit for shaping and amplifying the signal from the crank angle detection sensor 10. In this embodiment, a rectangular wave signal that alternately repeats rising and falling is generated as the rotational position signal S1 every time a pulse is applied from the crank angle detection sensor 10. The feature of the present invention resides in that the magnetic information synchronized with the rotational position signal S1 is recorded on the magnetic recording medium 3. The magnetic recording medium 3 is a layer fixed on the crankshaft 2 along the circumferential direction, and information can be magnetically recorded here. The signal recording means 30 gives a recording signal based on the rotational position signal S1 to the magnetic head 40. In this embodiment, the rotational position signal S1 indicates that the crankshaft 2 is 1
Since it is a rectangular wave signal that rises or falls every time it rotates, a magnetic pattern synchronized with this rectangular wave signal is recorded on the magnetic recording medium 3. The magnetic pattern thus recorded is reproduced by the signal reproducing means 50 via the magnetic head 40, and the signal reproducing means 50 is reproduced.
Outputs a reproduction signal S2. FIG. 3 is a conceptual diagram of a magnetic pattern recorded on the magnetic recording medium 3. The magnetic pattern indicated by the horizontal line in the figure is synchronized with the output signal of the crank angle detection sensor 10 indicating the rotational position of the crankshaft 2. Therefore, if the magnetic pattern is recorded while rotating the crankshaft 2, magnetic patterns at equal intervals can be obtained on the magnetic recording medium 3. An important point in the present invention is that this magnetic pattern is synchronized with the pulse output timing of the crank angle detection sensor 10. The magnetic recording medium 3 is, in this embodiment,
Although it is a layer fixed to the surface of the crankshaft 2, it is not limited to such a structure. For example, a flywheel or the like may be fixed to the crankshaft 2 and the magnetic recording medium 3 may be formed on the flywheel. In short, it suffices to form the magnetic recording medium 3 that is fixed to the crankshaft 2 in some form and that rotates as the crankshaft 2 rotates.

The rotational position signal S1 output from the rotational position detecting means 20 and the reproduction signal S2 output from the signal reproducing means 50 are given to the torque calculating means 60. The torque calculation means 60 calculates the torque generated in the crankshaft 2 based on these two signals. The principle is as follows. Now, it is assumed that a magnetic pattern is recorded on the magnetic recording medium 3 by the signal recording means 30 while the crankshaft 2 is rotating with no load. In this embodiment, a magnetic pattern is recorded at every rotation angle of 1 °. After making such a recording,
Consider a case where the signal reproducing means 50 reproduces this magnetic pattern. Now, assuming that the crankshaft 2 is in an unloaded state (that is, the state where the torque is 0), the rotational position signal S1 output by the rotational position detection means 20 and the reproduction signal S2 output by the signal reproduction means 50 are completely It will be synchronized. However, when a load is applied to the crankshaft 2 and a torque is applied, the crankshaft 2 is twisted, which causes a phase difference between the rotational position signal S1 and the reproduction signal S2. become. In other words, the twist angle can be obtained from this phase difference. The relationship between the torque value applied to the crankshaft 2 and the twist angle is as follows:
Since it is uniquely determined by the physical properties such as,
If the phase difference is detected, the applied torque value can be calculated.

FIG. 4 is a block diagram showing a concrete example of the configuration of the torque calculation means 60. Reference value calculation counter 61
Is supplied with a rotational position signal S1, and the phase difference calculation counter 62 is supplied with a rotational position signal S1 and a reproduction signal S2. Further, a predetermined clock signal is given to the counters 61 and 62 from the reference clock 63. The frequency of this clock signal is sufficiently higher than the frequencies of the signals S1 and S2. The reference value calculation counter 61 uses this clock signal to rotate the rotation position signal S.
An amount corresponding to a cycle of 1 (in this embodiment, a half cycle t of a rectangular wave as shown in FIG. 5) is counted as a reference value. On the other hand, the phase difference calculation counter 62 uses this clock signal to determine the amount of the phase difference between the rotational position signal S1 and the reproduction signal S2 (in this embodiment, as shown in FIG. And the amount of deviation Δt) at the time of falling is counted. The reference value t thus counted is used as the rotation speed calculator 6
4 and the torque calculator 65, and the phase difference Δt is given to the torque calculator 65. The rotation speed calculator 64 calculates the rotation speed R by multiplying the reference value t by a predetermined coefficient K1.
Calculate θ. The torque calculator 65 obtains the phase difference between both signals as (Δt / t), and a predetermined coefficient K2 is added to this phase difference.
The torque Tθ is calculated by multiplying by (a value that is uniquely determined by the physical properties such as the material and thickness of the crankshaft 2).

Thus, in the torque calculation means 60,
The rotation speed Rθ is obtained together with the torque Tθ, but the important point here is that the signal S is always obtained when these values are obtained.
It is synchronized with 1. That is, the torque Tθ and the rotation speed Rθ are obtained in synchronization with the timing at which the crank angle detection sensor 10 generates a pulse. Therefore, when performing calculations for ignition timing control and air-fuel ratio control each time the crank angle detection sensor 10 generates a pulse, without performing any special synchronization processing,
The obtained torque value can be used for calculation. Further, since the recording of the magnetic pattern on the magnetic recording medium 3 can be performed at any time, an error in mounting the crank angle detection sensor 10, an error due to a change with time, and the like can be removed by recording a new magnetic pattern. , You can always get accurate torque value. FIG. 6 is a result showing changes in the torque value Tθ and the rotational speed Rθ when the above-described torque detection device is applied to a 4-cylinder spark engine. It can be seen that the generated torque fluctuation and rotation fluctuation for each cylinder are completely synchronized with the crank angle. In this way, by extracting the parameters of torque fluctuation and rotation fluctuation that are synchronized with the crank angle, it is possible to perform more optimal calculations for ignition timing control and air-fuel ratio control.

Finally, the torque detection device according to the present invention is
An embodiment applied to a robot manipulator using an electric motor is shown in FIG. An arm 6 is attached to the tip of a manipulator shaft 5 which is rotationally driven by a motor 4 (gear or the like is not shown), and a rotary encoder 70 is provided to detect the rotational position of the manipulator shaft 5. There is. The rotary encoder 70 is not specially installed for the torque detecting device according to the present invention, but is an existing device for controlling the robot manipulator. In order to incorporate the torque detecting device according to the present invention into such a robot manipulator, the magnetic recording medium 3 may be fixedly formed on the manipulator shaft 5. The rotary position detecting means 20 outputs the pulse signal output from the rotary encoder 70.
The rotational position signal S1 detected by the signal recording means 3 is detected.
0, and a magnetic pattern synchronized with this is recorded on the magnetic recording medium 3 by the magnetic head 40. This magnetic pattern is reproduced by the signal reproducing means 50 using the magnetic head 40 to obtain a reproduced signal S2. The torque calculation means 60 calculates the torque on the basis of the rotational position signal S1 and the reproduction signal S2 obtained in this way, which is exactly the same as the above-described embodiment. In this torque detection device, since the torque value synchronized with the output of the rotary encoder 70 is detected, the torque value synchronized with the control timing of the motor 4 is used for the control as it is, and the optimum motor control suitable for the generated load can be performed. It will be possible. Further, in this torque detection device, since it is not necessary to intervene a special mechanical element, the relationship between the torque and the load has a substantially linear relationship, and the control system can be simplified.

Although the present invention has been described above based on the illustrated embodiments, the present invention is not limited to these embodiments and can be implemented in various modes other than this. For example, in the above-described embodiment, the torque detecting device according to the present invention is applied to the robot manipulator, but the present invention is also applicable to a machine tool that performs cutting in addition to this.

[0019]

As described above, according to the torque detecting device of the present invention, accurate torque detection can be performed in synchronization with the rotational position of the power shaft of the power generating engine.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment in which a torque detection device according to the present invention is applied to an automobile engine.

FIG. 2 is a diagram showing an example of a crank angle detection sensor in the torque detection device shown in FIG.

FIG. 3 is a detailed view of the periphery of the magnetic recording medium in the torque detection device shown in FIG.

4 is a block diagram showing a configuration example of a torque calculation means in the torque detection device shown in FIG.

5 is a waveform diagram for explaining the operation of the torque calculation means shown in FIG.

FIG. 6 is a graph showing the detection results of the torque value Tθ and the rotation speed Rθ when the torque detection device shown in FIG. 1 is applied to a 4-cylinder spark engine.

FIG. 7 is a block diagram showing an embodiment in which the torque detection device according to the present invention is applied to a robot manipulator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Crank shaft 3 ... Magnetic recording medium 4 ... Motor 5 ... Manipulator shaft 6 ... Arm 10 ... Crank angle detection sensor 11 ... Light emitting diode 12 ... Light receiving diode 13 ... Signal disk plate 20 ... Rotation position detection means 30 ... Signal Recording means 40 ... Magnetic head 50 ... Signal reproducing means 60 ... Torque calculating means 61 ... Reference value calculating counter 62 ... Phase difference calculating counter 63 ... Reference clock 64 ... Rotation speed calculator 65 ... Torque calculator 70 ... Rotary encoder S1 ... Rotation Position signal S2 ... Playback signal

Claims (3)

[Claims] 1. A torque detection device for detecting a torque acting on a power shaft of a power generating engine, comprising: rotational position detection means for detecting a rotational position of the power shaft; and magnetic recording fixed on the power shaft. A medium, a magnetic head for recording and reproducing a predetermined signal with respect to the magnetic recording medium, and predetermined magnetic information based on a detection signal of the rotational position detecting means is recorded on the magnetic recording medium using the magnetic head. A signal recording unit, a signal reproducing unit for reproducing magnetic information recorded on the magnetic recording medium by using the magnetic head, a detection signal of the rotational position detecting unit, and a reproduction signal of the signal reproducing unit. And a torque calculation unit that calculates a torque acting on the power shaft based on the phase difference. 2. The torque detecting device according to claim 1, wherein the power generating engine is an internal combustion engine, and a crank angle detecting sensor provided in the internal combustion engine is used as a rotational position detecting means. Detection device. 3. The torque detecting device according to claim 1, wherein the power generating engine is an electric motor, and a rotary encoder provided on a rotary shaft of the electric motor is used as a rotational position detecting means. apparatus.