JPH0474659B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a rotational fluctuation tester that simulates the power transmission of a reciprocating engine such as an engine, and particularly
Simulation of transmission parts whose angular velocity and torque change periodically, such as automobile toothed belts that interlock the camshaft and crankshaft of OHC and DOHC engines, chains, couplings, and gears driven by diesel engines and other sources. The present invention relates to a rotational fluctuation testing machine that tests the performance of the above-mentioned transmission components by subjecting them to rotational fluctuation or torsional vibration.

(Prior art) Gears, chains, belts, couplings, etc. driven by the crankshaft of reciprocating machines such as engines,
Performance tests of a series of power transmission mechanisms such as bearings and dampers generally do not use actual engines due to safety, noise, and control characteristics issues, but instead use test equipment that uses an electric motor as the power source.

However, while electric motors rotate smoothly with small changes in angular velocity, engines and the like have rotational characteristics in which angular velocity periodically changes due to the presence of top and bottom dead centers, explosion exhaust, and the like.

Therefore, simply replacing the engine as the driving source of the test equipment with an electric motor has the drawback that the stress applied to the test object is smaller than the actual stress, resulting in test results that are far from reality.

Therefore, the inventor first used an electric motor as a drive source,
We proposed a rotational fluctuation tester that applied the Cardan error of a universal joint as a rotational fluctuation tester that outputs rotational force with a change in angular velocity (Patent application No. 145758, 1986).
No., Special Application No. 117792 of 1988).

The rotational variation testing machine disclosed in the above-mentioned patent application transmits rotational force from an electric motor to an output shaft via a universal joint that is set at a predetermined angle.

(Problems to be Solved by the Invention) The rotational variation testing machine of the prior art has the advantage of being able to output rotations that change arbitrary angular velocity using simple means.

However, when compared with the power transmission of an actual engine, there are still differences in transmission characteristics that cannot be ignored. For example, the toothed belt and gears that transmit power between the crankshaft and camshaft in an OHC engine, and the transmission mechanism used to drive other reciprocating coolers etc. by the engine, respond to periodic changes in the angular velocity of the drive source. In addition, periodic changes in torque due to load characteristics are applied.

That is, in the transmission mechanism exemplified above, the load torque changes periodically due to changes in the pressure angle due to rotation of the cam and compression exhaust from the compressor. In contrast, conventional rotational fluctuation testing machines can output changes in angular velocity on the drive side, but cannot produce changes in torque, so these tests lack practicality, and improvements have been desired.

The present invention focuses on these drawbacks of conventional rotational fluctuation testing machines, and aims to propose a rotational fluctuation testing machine that has characteristics closer to those tested using an engine or the like under an actual load.

(Means for Solving the Problems) One of the structural features of the present invention for achieving the above-mentioned object is that it has an input shaft and a load shaft, and a This is a rotational variation testing machine in which the main power transmission mechanism is fitted, and the input shaft is connected to the prime mover via a universal joint set at an arbitrary angle, while the load shaft is connected to a constant control. The rotational fluctuation tester is connected to a brake that can apply power intermittently in short periods of time, and another feature is that it has an input shaft and a load shaft, and a power transmission mechanism that is the object to be measured is placed between the two shafts. The input shaft is connected to an electric motor whose rotational speed can be changed periodically, while the load shaft can apply a constant braking force intermittently within a short period of time. There is a rotation variation test machine connected to the brake that can be used.

The input shaft in the present invention is connected to the electric motor via a universal joint set at an angle of inclination, or the electric motor itself can periodically change the angular velocity. It rotates with a periodic change in angular velocity.

On the other hand, since a constant braking force can be applied intermittently to the load shaft within a short period of time, the torque required to rotate the load changes periodically.

Therefore, the power transmission mechanism fitted between the input shaft and the load shaft is subjected to periodic load torque fluctuations in addition to periodic angular velocity changes due to the driving source, and when rotated by an engine etc. Driving tests are conducted under these conditions.

(Example) Specific examples of the present invention will be further described below.

FIG. 1 is a front view of a rotational fluctuation tester in a specific embodiment of the present invention, FIG. 2 is a front view of the input shaft drive device shown in FIG. 1, and FIG. 3 is a front view of the input shaft drive device shown in FIG. 4 is a perspective view of the universal joint; FIG. 5 is a block diagram of the load brake of FIG. 1; and FIG. 6 is a second embodiment of the input drive. It is a front view of the seventh
6 is a plan view of the input shaft drive device of FIG. 6, FIG. 8 is a front view of a third embodiment of the input shaft drive device, and FIG. 9 is a front view of a fourth embodiment of the input shaft drive device. FIG. 10 is a front view of a rotational fluctuation tester using the input shaft drive device of the fifth embodiment, and FIG.
The figure is a block diagram of the input circuit of the motor used in the embodiment shown in FIG.

In FIG. 1, numeral 30 is a rotational fluctuation tester in a specific embodiment of the present invention. The rotational fluctuation tester 30 of this embodiment has an input shaft drive device 1 that rotates an input shaft 31 with a constant periodic angular velocity change, and a load shaft 32 to which a braking force is applied intermittently at a constant period. It is something. In this embodiment, the input shaft drive device 1 includes a moving base 10 as shown in FIG.
The input shaft 6 of a universal joint 5 as shown in FIG. The output shaft 7 of the universal joint 5 is held at the same height as the output shaft of the drive motor 2 by a bearing 8, and is extended as an input shaft 9. It is. The movable base 10 is a steel plate to which the drive motor 2 is fixed with bolts or the like, and is fixed on a rotary table 11 also made of a rectangular steel plate.
The rails 13 are connected to the linear guide rails 13 of the book through two linear bearings 14 respectively.
can freely move linearly along the axis.

Further, the rotary table 11 has a rotation center 22 directly below the center of the top 51 on the yoke 50 of the universal joint 5, and a worm wheel 17 disposed on the base 16 so as to be rotatable in a direction parallel to the base 16. It is fixed to the upper surface of the block 18 via a block 18.

Further, the rear part of the rotary table 11 is engaged with the upper end of a rail 19 provided on the base 16 in an arc shape around the rotation center of the worm wheel 17, and can be held at any position by a fastening member (not shown). Rotary table 11 can be fixed to rails 19. Further, a worm 21 connected to a handle 20 is engaged with the worm wheel, and is rotatable around a rotation center 22.
By manually rotating the handle 20, the rotary table 11 can be moved in an arc while engaging with the rail 19, and the universal joint 5 can be given an arbitrary inclination angle.

In the above embodiments, the moving base 10 uses rails and linear bearings as the most preferred example, but other known linear motion devices such as those using wheels, rollers, bronze alloys, etc. Materials with good lubricity such as molybdenum and nylon, rollermite, etc. can be used.

The input shaft drive device 1 is coupled via a linear bearing 33 to a main body base 55 of the rotation variation testing machine 30 so as to be linearly movable back and forth in the direction of arrow A.
Also, a stopper 34 is provided with a female thread at the end of the main body base 55 and on the side of the input shaft drive device 1.
is fixed, and the stopper 34 has a handle 3 at one end.
A screw 36 to which 5 is fixed is fitted.

Furthermore, the tip of the screw 36 and the input shaft drive device 1
are connected via a load cell 37, and by rotating the handle 35, the input shaft drive device 1 can be moved along the linear bearing 38.
Further, the tensile force at that time can be detected by the load cell 37.

One load shaft is arranged parallel to the input shaft 31 and rotatably supported on the main body base 55 by a bearing 38, and is preferably connected to a torque detector 39 and an eddy current brake 40 using non-backlash couplings 41, 4.
2.

Here, the eddy current brake 40 is one in which an excitation coil and an eddy current ring are arranged around a rotor. The rotation of the rotor generates an eddy current within the eddy current length, and this eddy current applies a control force to the rotor.

In addition, the input shaft of the eddy current brake 40 has a load shaft 32.
A rotation sensor 46 is provided to detect the angular velocity of. As shown in FIG. 5, another pulse generation circuit 83 of the rectifier circuit 82 is connected to the excitation coil of the eddy current brake, and a sawtooth pulsating current is input thereto.

Further, if the pulse generation circuit generates a constant pulse in response to the rotational speed or rotation angle of the load shaft detected by the rotation sensor 46, characteristics closer to actual transmission can be reproduced.

Next, the operation of each part of the rotational fluctuation tester of this embodiment will be explained using a running test of a toothed belt as an example. A toothed belt 43, which is a test object, has a toothed pulley 44, which is locked to an input shaft 31 and a load shaft 32, respectively.
45 is fitted. First, in preparation for the test, the toothed belt 43 is suspended between the toothed belts 43 and 44, and the handle 35 is rotated to apply a predetermined initial tension to the toothed belt 43.

Further, the handle 20 of the input shaft drive device 1 is rotated to give a predetermined crossing angle to the universal joint. In this state, the electric motor 2 is started. At this time, the input shaft 31 rotates with periodic angular velocity changes due to the Cardan error of the universal joint. This rotation directly rotates the toothed belt via the toothed pulley 44. Then, the toothed belt 43 rotates the load shaft 32 via the pulley 45, and rotates the vortex brake 40. Incidentally, since a pulsating current corresponding to the rotation angle of the load shaft detected by the rotation sensor 46 is passed through the excitation coil of this eddy current brake, a periodic load is applied to the toothed belt, which is a test material, by the eddy current brake.

In the above embodiments, an eddy current brake was used as a brake for applying a pulsating load to the load shaft. This is because the rotational fluctuation tester of the present invention often operates continuously over a long period of time due to its nature, so it is desirable that the brakes also be able to maintain the same performance over a long period of time.

From this point of view, the eddy current brake is most desirable because it uses eddy current to generate load torque, is mechanically non-contact, and does not change performance due to wear.

However, depending on the application, it is also possible to use a contact type brake, such as a disc brake consisting of a rotating disc and disc pads sandwiching it to apply frictional force, in which the disc pads are applied periodically. . In this embodiment, the input shaft drive device is exemplified as one in which the electric motor 2 is installed on a movable base 10 that is movable in the axial direction. We focused on the fact that when a universal joint is rotated at an angle of inclination, displacement in the axial direction actually occurs, and we adopted this method to release that displacement and ensure smooth rotation. be.

This configuration has a feature that the device has a long lifespan because no unreasonable force is generated in each part even when the input shaft is rotated with a considerably large torque. However, when using it with a relatively low torque, the moving base Alternatively, the electric motor may be directly fixed (FIGS. 6 and 7).

However, even in this case, it is desirable to use a shaft joint 80 that connects the universal joint and the motor that allows a certain degree of axial displacement. Examples of shaft joints that allow displacement in the axial direction include elastic couplings and chain couplings that connect input shafts with an elastic body interposed therebetween.

It is also effective to provide elasticity to the shaft side by providing a spline 81 on one side of the input/output shaft of the universal joint as shown in Figure 9, without giving the shaft joint itself any permissible capacity in the axial direction. be.

Further, it is preferable that the electric motor and the universal joint be connected by a means that does not cause backlash, such as a slip such as a V-belt, a gear, or a chain. The best results can be obtained when a fixed shaft joint is used for direct connection as in this embodiment.

This is because this device generates rotation with a change in angular velocity, so during the change, the input shaft receives rotational force in the opposite direction to the rotation direction due to the inertia of the test sample, causing belt slippage and backlash. This is because, in some cases, rotational fluctuations of the shaft on the input side of the universal joint are not transmitted to the output side, and the rotation of the input and output shafts is smoothed out.

However, it goes without saying that the present invention does not exclude the use of a belt or the like between the electric motor and the universal joint. (However, there is a drawback that distortion is added to the fluctuating waveform of the output shaft.) In this example, only one universal joint is used, but in some cases an eighth universal joint may be used.
It is also possible to use two or more universal joints 5', 5'' as shown in the figure.When using two or more universal joints, the angular velocity change can be increased.However, in this case It is necessary to design so that the angles formed by the intermediate axis sandwiched between two universal joints and the other axis are not equal to each other, or so that the two universal joints are not on the same plane.

It should be noted that when configured as described above, the angular velocity displacements cancel each other out, resulting in no fluctuation in the angular velocity.

Moreover, the same left-handed effect can be obtained by providing the electric motor itself with a function of periodically changing the angular velocity instead of using a universal joint as in the above-described embodiment.

The above-mentioned electric motor can simply be achieved by periodically varying the input voltage of a DC motor, or by varying the frequency of the input power supply in an induction motor. However, more preferably, as an input power source for an induction motor, in addition to periodically pulsating its frequency, the rotation speed of the motor is detected moment by moment, and this detected value and the basic rotation speed or the pulsation of the input power source are used. It is recommended to adopt a circuit that compares the number of revolutions theoretically calculated from the momentary frequency of the motor and passes current to the motor according to the comparison value.

According to the above circuit, the electric motor generates a torque corresponding to the deviation between the target rotational speed and the actual rotational speed, so that the electric motor can more quickly follow the target rotational speed.

A specific example of the above circuit will be given below.

FIG. 11 is a block diagram of an input circuit for a motor used in a specific embodiment of the present invention. In the figure, 60 is a DC power supply that is smoothly adjusted by a rectifier circuit (not shown). 61 is a current control circuit that increases or decreases the amount of current according to a signal from a belt control circuit 62, and 63 is a current control type inverter that controls the frequency and phase of the DC power controlled by the current control circuit 61 and converts it into AC power. The induction motor 64 is controlled by this current, frequency, and phase controlled inverter 6.
3 output power is input. Reference numeral 46 denotes the rotation detecting device described above, and as in the previous embodiment, it is arranged near the end of the load shaft. Reference numeral 65 denotes a speed setter for setting a predetermined constant rotation speed, and the signal from the speed setter 65 and the signal from the rotation detection device 46 are input to a deviation amplification circuit 66. In the deviation amplification circuit 66, the difference between both signals is amplified. 67 is a pulsating signal generation circuit that generates a pulsating output signal, 68 is a pulsating frequency setter that sets the frequency thereof, and 69 is a pulsating amplitude setting device that similarly sets the amplitude of the pulsating signal. 70 is a deviation amplification circuit 66 and a pulsation generation circuit 67
An adder circuit that adds signals output from both sides. Reference numeral 62 denotes a vector control circuit that performs calculations for increasing/decreasing the frequency of the current value input to the induction motor 64 from moment to moment based on the output signal of the adding circuit 70 and the rotation signal of the rotation detection device 46. An inverter control circuit 71 inputs the frequency command signal and phase command signal of the vector control circuit 62 to control the inverter 63, and controls the output frequency and phase of the inverter 63 based on this output signal.

(Effects) The rotation fluctuation test of the present invention involves rotating the input shaft with periodic angular velocity changes based on the Cardan error of the universal joint and electrical signals, and applying a load that changes periodically to the load shaft. As if a reciprocating engine such as an engine were used as a driving source,
This has the effect of imparting the same motion to the object to be measured as when power is transmitted to a cooler or camshaft.

By using the rotational fluctuation tester of the present invention, it is possible to perform a running test on a power transmission mechanism used for an engine or the like without using an actual engine, camshaft, or the like.

[Brief explanation of drawings]

FIG. 1 is a front view of a rotational fluctuation tester in a specific embodiment of the present invention, FIG. 2 is a front view of the input shaft drive device shown in FIG. 1, and FIG. 3 is a front view of the input shaft drive device shown in FIG. 4 is a perspective view of the universal joint; FIG. 5 is a block diagram of the load brake of FIG. 1; and FIG. 6 is a second implementation of the input shaft drive. FIG. 7 is a plan view of the input shaft drive device of FIG. 6;
FIG. 8 is a front view of the third embodiment of the input shaft drive device, FIG. 9 is a perspective view of the universal joint in the fourth embodiment of the input shaft drive device, and FIG. 10 is a front view of the fifth embodiment of the input shaft drive device. It is a front view of the rotation fluctuation test machine using the input shaft drive device of the 11th example.
This figure is a block diagram of the input circuit of the motor used in the embodiment shown in FIG. 10. 1... Input shaft drive device, 2... Drive motor, 5... Universal joint, 30... Rotation fluctuation tester,
31...Input shaft, 32...Load shaft, 40...Eddy current brake.

Claims (1)

[Scope of Claims] 1. A rotational fluctuation tester having an input shaft and a load shaft, in which a power transmission mechanism as an object to be measured is fitted between the two shafts, wherein the input shaft can be positioned at any angle from the prime mover. A rotation variation testing machine characterized in that the load shaft is connected via a universal joint that is set at an angle, and the load shaft is connected to a brake that can apply a constant braking force intermittently within a short time. . 2. A rotation variation testing machine that has an input shaft and a load shaft, and a power transmission mechanism as the object to be measured is fitted between the two shafts, and the input shaft is an electric motor whose rotation speed can be changed periodically. A rotation variation tester characterized in that the load shaft is connected to a brake that can apply a constant braking force intermittently within a short period of time.