JP3940326B2 - How to adjust the balance testing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a balance testing machine for measuring an unbalance of an asymmetric rotor whose weight distribution is not symmetric with respect to an axis of rotation such as an asymmetric crankshaft, and more particularly to a method for adjusting measurement performance or measurement operation of a balance testing machine. Is.
[0002]
[Prior art]
Among the crankshafts that are the main components of an internal combustion engine, there is a so-called asymmetric crankshaft. The asymmetric crankshaft is represented by, for example, a crankshaft of a three-cylinder or V-6 engine, and the weight distribution is not symmetrically distributed with respect to the rotation axis, and the weight distribution is asymmetric with respect to the rotation axis. . Such an asymmetric crankshaft alone has an inherent unbalance due to an asymmetric weight distribution, and has a moment (referred to as a free moment) due to a dynamic unbalance during rotation. When measuring such a rotational imbalance of the asymmetric crankshaft, a large vibration occurs due to the free moment, so various measures are required for processing the free moment.
[0003]
More specifically, the asymmetric crankshaft does not have to balance the rotational unbalance with the crankshaft alone, and the rotational unbalance is balanced with the piston and connecting rod attached to the crankshaft. There is a need. For this reason, conventionally, there has been a method of measuring rotational imbalance after compensating a free moment by attaching a connecting rod or a dummy weight equal to the weight of the piston attached to each crankpin of the crankshaft. there were.
[0004]
However, this method is often difficult to automate because the dummy weight is often attached and detached manually. In addition, if an apparatus that realizes automatic attachment and removal of dummy weights is to be manufactured, there is a drawback in that the apparatus is very complicated and becomes a high-cost apparatus as a whole. In addition, it takes time to attach and detach the dummy weight, and there is a drawback in that the measurement time of rotation imbalance of one crankshaft, so-called cycle time is long.
[0005]
In view of this, there has been proposed a balance testing machine in which a compensation weight for canceling the free moment of the asymmetric crankshaft is attached to the rotational drive system of the balance testing machine (for example, JP-A-7-167219 and JP-A-7-306112). ).
In such a balance testing machine, the asymmetric crankshaft for measuring the unbalance and the compensation weight are rotated synchronously, so that the free moment of the asymmetric crankshaft and the rotation moment of the compensation weight are offset, and the vibration table is caused by the free moment. The vibration that does not appear.
[0006]
[Problems to be solved by the invention]
In the prior art provided with a compensation weight in the rotary drive system, there is a problem that it is difficult to change the setup when there are a plurality of types of asymmetric rotors for measuring unbalance.
In addition, changes in the mass distribution of the drive system may occur during use of the balance testing machine (for example, chips etc. contained in the cutting oil adhere to the rotary drive system and dry to change the mass). It was. In order to correct such a change in the mass distribution of the drive train, a plurality of asymmetric rotors (master rotors) prepared for each type of asymmetric rotor for measuring the imbalance and adjusted to the correct imbalance are periodically used. The balance is set on the balance tester and the unbalance is measured. If the measurement result is normal, it should be zero, but if the mass distribution has changed, the measurement result also changes accordingly. Therefore, the amount of change obtained from the measurement result has been electrically compensated.
[0007]
For this reason, a master rotor must be prepared for each of a plurality of types of asymmetric rotors for which unbalance is to be measured, and the balance testing machine must be periodically adjusted using the prepared master rotors. There was a problem of taking time. Further, there is a problem that it is difficult to store the plurality of master rotors. The main object of the present invention is based on the above background, and is to provide a method in which the balance tester can be easily adjusted in a single time.
[0008]
Another object of the present invention is to adjust a balance testing machine for a plurality of types of asymmetric rotors to be measured by preparing one correction master rotor when there are a plurality of types of asymmetric rotors to be measured. It is to provide an adjustment method as described above.
[0009]
[Means for Solving the Problems and Effects of the Invention]
The invention according to claim 1 is an adjustment method for a balance testing machine that measures unbalance of an asymmetric rotor whose weight distribution is not symmetric with respect to the rotation axis, and there are a plurality of types of asymmetric rotors that measure unbalance, The balance testing machine is provided with a compensation weight for canceling the vibration in the rotary drive system in order to cancel the vibration caused by the inherent unbalance caused by the weight distribution of the predetermined asymmetric rotor. With respect to the plurality of types of asymmetric rotors to be measured, measurement results output from the balance tester when the unbalance distribution is correct are measured and stored in advance as reference values, and the unbalance distribution is predetermined. One correction master rotor adjusted to the above condition is prepared, and the correction master rotor is measured by the balance testing machine every time a predetermined measurement time comes. Then, the measurement result is stored, and the amount of change in the measurement result of the correction master rotor obtained from the previous measurement result and the current measurement result is added to the reference value of each asymmetric rotor, thereby measuring the unbalance. The balance testing machine adjustment method is characterized in that reference values of the plurality of types of asymmetric rotors to be corrected are respectively corrected.
[0010]
The invention according to claim 2 is characterized in that the correction master rotor is made by any one of the plurality of types of asymmetric rotors whose unbalance should be measured. Is the method.
The invention according to claim 3 is the adjustment method for a balance testing machine according to claim 1 or 2, wherein the unbalance distribution in the correction master rotor is a state in which the unbalance distribution is correct. It is.
[0011]
According to the first aspect of the present invention, one correction master rotor is prepared, and every time a predetermined measurement time comes (for example, every time a predetermined number of asymmetric rotors are unbalanced, a predetermined measurement time elapses). Or every time an abnormal signal or the like is output from the apparatus, etc., the correction master rotor is set on the balance testing machine, the unbalance is measured, and the measurement result is stored. When adjustment of the balance testing machine is normal, the measurement result obtained by measuring the correction master rotor is a predetermined value. However, when the mass distribution changes due to, for example, cutting scraps adhering to the rotational drive system of the balance testing machine, the measurement result changes from a predetermined value.
[0012]
This change is the result when measuring the unbalance of the correction master rotor, but when measuring the types of asymmetric rotors whose unbalance is to be measured, the unbalance distribution is adjusted to the correct state. Can also be assumed to change in the same manner.
Therefore, in the present invention, measurement is performed in advance based on the premise that, as a result of measuring the unbalance of one correction master rotor, the amount of change in the measurement results also appears in the measurement results of a plurality of types of asymmetric rotors. The reference values of a plurality of types of asymmetric rotors stored in the memory are respectively corrected.
[0013]
With such correction, the reference values for a plurality of types of asymmetric rotors to be measured can be corrected based on the unbalance measurement result of one correction master rotor, so that the time required for adjustment of the balance testing machine can be only one hour. Since it is sufficient to prepare one correction master rotor, it is easy to store it.
It is practically convenient to prepare one correction master rotor to be prepared by any one of the asymmetric rotors to be measured for imbalance.
[0014]
In addition, it is desirable for correction processing of the reference value that one correction master rotor to be prepared is set so that the balance distribution is in a correct state as in the third aspect.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a vibration bridge of a balance testing machine to which an adjustment method according to an embodiment of the present invention can be applied, and is described in JP-A-7-167219 except for an electrical block diagram portion. It is the same composition as what is.
[0016]
The vibration bridge 10 is held by a spring 20 so as to vibrate. A bearing head 1 is planted on the upper left of the vibration bridge 10, and a projecting shaft 2 that protrudes horizontally to the right is supported by the bearing head 1. A drive frame 3 is rotatably mounted around the protrusion shaft 2 by a ball bearing 12. The drive frame 3 is rotated by the rotation drive unit 11. A protruding portion 13 protrudes from the lower end of the protruding shaft 2, and a rotating roller 14 is provided at the end.
[0017]
A gantry post 16 is erected on the upper right of the vibration bridge 10 via a fixed leg 17. A bearing roller 9 is provided at the upper end of the gantry post 16.
An asymmetric rotor, such as a crankshaft 15, for which unbalance measurement is performed, is rotatably held at both ends by a rotating roller 14 and a bearing roller 9. In the holding state, the rotation axis 8 of the crankshaft 15 is set so as to be aligned with the rotation axis of the drive frame 3.
[0018]
The linkage lever 6 extends from the tip of the drive frame 3, and the tip clamp of the linkage lever 6 is engaged with one crankpin 7 of the crankshaft 15. For this reason, when the drive frame 3 is rotated, the crank pin 7 is rotated by the cooperation lever 6, and the crankshaft 15 is rotated synchronously with the drive frame 3.
The drive frame 3 is provided with fixed weights 5 and 5 'and turning weights 4 and 4'. These fixed weights 5 and 5 ′ and turning weights 4 and 4 ′ are compensation weights.
[0019]
The crankshaft 15 is an asymmetric rotor whose weight distribution is not symmetric with respect to the rotation axis 8. Therefore, when the crankshaft 15 is rotated, vibration is generated by a free moment due to dynamic imbalance caused by the weight distribution. The fixed weights 5 and 5 'and the turning weights 4 and 4' as compensation weights cancel out this vibration.
In order to measure the unbalance of a plurality of types of asymmetric rotors using such a balance tester, the balance tester must be used after making the following adjustments.
[0020]
(1) A dummy weight with a specified mass on the first type of crankshaft (asymmetric rotor) (the dummy weight is the mass and moment of the connecting rod, piston, etc. mounted on the crankpin as the mass of the crankpin) An unbalance measurement is carried out by attaching a weight, which is attached to a crank pin, and a master rotor 1 corrected so that the unbalance is zero is prepared.
[0021]
(2) Set the master rotor 1 on the balance testing machine and perform master correction. The master correction is to adjust the compensation weight (specifically, the turning weights 4, 4 ′, not the fixed weights 5, 5 ′) of the balance testing machine so that the measurement result of the master rotor 1 becomes zero. . Further, when the measured value of the master rotor 1 does not become zero by mechanical adjustment, the measured value is stored as a reference value, and the balance measurement result can be corrected based on the reference value.
[0022]
(3) As for the second type crankshaft (asymmetric rotor), the master rotor 2 is prepared and the master correction is performed by the master rotor 2 in the same manner as the first type crankshaft.
Similarly, for the third type crankshaft (asymmetric rotor), the master rotor 3 is prepared, and master correction is performed using the master rotor 3.
[0023]
A similar process is performed for all of the types of crankshafts (asymmetric rotors) to be measured.
(4) Set the type of crankshaft to be measured and measure the unbalance.
(5) Correct the unbalance of the crankshaft according to the unbalance measurement value. In this case, as the unbalance measurement value, a value electrically corrected based on the reference value is used.
[0024]
(6) Periodically or if a malfunction occurs, set the master rotors 1, 2, 3, ... that have undergone master correction to the balance testing machine in order to check the unbalance of the entire rotating system. To do. Then, the compensation weight (specifically, the turning weights 4, 4 ') is adjusted and / or the reference value is corrected.
Thus, in order to measure the unbalance of a plurality of types of asymmetric rotors, the balance testing machine must be adjusted using the master rotors of the plurality of types of asymmetric rotors, which requires time and effort. There was a drawback.
[0025]
In the present invention, according to the flowchart shown in FIG. 2, the balance testing machine can be adjusted easily and in a short time by using one correction master rotor.
In the balance testing machine of FIG. 1, unbalance measurement results are given to the control unit 23 from the vibration detector 21 and the reference signal generator 3.
[0026]
FIG. 2 is a flowchart showing a control operation performed by control unit 23 of FIG.
As an initial setting process, the control unit 23 performs master alignment for all types (all models) of asymmetric rotors to be measured, and measures the correction master rotor and stores the measurement value (A) (step S0).
Specifically, as described in (1) to (3) above, a plurality of types of crankshaft master rotors 1, 2, 3,... The reference value is measured and stored in the memory 24. The initial reference values are stored as rotor 1, rotor 2, rotor 3,... For each type. The measured value (A) of the correction master rotor is also stored in the memory 24.
[0027]
After the initial setting is completed, the balance testing machine is automatically operated, and when the crankshaft unbalance measurement for each type and the unbalance correction processing are performed for a predetermined time (steps S1 and S2), the correction mode is set. In the correction mode, the correction master rotor is measured, and its value (B) is stored (step S3).
Next, the measurement value (A) of the correction master rotor stored in the initial setting (step S0) and the measurement value (B) of the correction master rotor measured in step S3 are compared. Alternatively, if the difference is within a predetermined allowable range, the unbalance measurement / correction operation from step S1 is repeated (YES in step S4).
[0028]
However, if the initial measurement value (A) is different from the measurement value (B) measured in step S3, or if it differs beyond a predetermined tolerance, the difference (B−A) is obtained as a correction value difference. (Step S5), a value obtained by adding a correction value difference to the initial reference values (rotor 1, rotor 2, rotor 3,...) Of a plurality of types of rotors stored in the memory 24 as new reference values. Store in the update value area of the memory 24 (step S6).
[0029]
In the subsequent unbalance measurement, the unbalance correction is performed using the updated new reference value.
The measured value (B) of the correction master rotor obtained in step S3 is overwritten and stored as (A) 'on (A) (step S7).
As a result, the unbalance correction of each type of asymmetric rotor is performed using the reference value.
[0030]
The reason for using the reference value is as follows. When unbalance measurement is performed for each type of master rotor 1, 2, 3,..., The measurement result obtained is not necessarily zero. This is because when the compensation weights 5, 5 ', 4, 4' are set so as to cancel the vibration caused by the free moment of a certain kind of crankshaft, if the kind of the crankshaft is changed, the compensation weights 5, 5 ', 4, 4 The vibration canceling effect due to 4 'is not completely achieved. Therefore, a certain unbalance amount and angle appear in the measurement result. This value is considerably small due to the use of the compensation weight. For example, if the unbalanced moment of a 6-cylinder crankshaft is set to 7,000 gr · cm, whereas the unbalance allowable value is 10 gr · cm, the remaining unbalance, for example, is about 300 gr · cm. Has been reduced. Therefore, the remaining unbalance is electrically compensated using the reference value to obtain the correction amount.
[0031]
The reference value is stored for each rotor type to be measured, and is updated by using one correction master rotor. Therefore, without adjusting the compensation weights 5, 5 ', 4, 4' in the balance tester, the balance tester can be adjusted by using one correction master rotor to measure unbalance of a plurality of types of asymmetric rotors. Is possible.
[0032]
The correction master rotor is desirably made of any kind of asymmetric rotor whose unbalance is to be measured, and is preferably adjusted so that the unbalance distribution is normal.
The present invention is not only applicable to the balance tester described with reference to FIG. 1, but is also applicable to other balance testers described in the prior art.
[0033]
For example, a first rotational drive system having a compensation weight for canceling the free moment of one kind of asymmetric rotor and a second rotational drive having a compensation weight for canceling the free moment of another kind of asymmetric rotor The present invention can also be applied to a balance testing machine (for example, as described in Japanese Patent Laid-Open No. 7-306112) in which there is a system and these are operated selectively or cooperatively. .
[0034]
The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a vibration bridge of a dynamic balance testing machine to which an adjustment method according to an embodiment of the present invention can be applied.
FIG. 2 is a flowchart showing a control operation performed by control unit 23 of FIG.
[Explanation of symbols]
3 Drive frame 4, 4 'Turning weight (compensating weight)
5,5 'fixed weight (compensating weight)
21 vibration detector 22 reference signal generator 23 control unit 24 memory

Claims (3)

An adjustment method for a balance testing machine for measuring the unbalance of an asymmetric rotor whose weight distribution is not symmetrical with respect to the rotational axis,
There are multiple types of asymmetric rotors that measure unbalance,
The balance testing machine is provided with a compensation weight for canceling the vibration in the rotary drive system in order to cancel the vibration caused by the inherent unbalance caused by the weight distribution of the predetermined asymmetric rotor,
For the plurality of types of asymmetric rotors whose unbalance is to be measured, measurement results output from the balance testing machine when the unbalance distribution is correct are measured and stored in advance as reference values,
Prepare one correction master rotor in which the unbalance distribution is adjusted to a predetermined state,
Every time a predetermined measurement time comes, measure the correction master rotor with the balance testing machine, store the measurement result,
By adding the amount of change in the measurement result of the correction master rotor obtained from the previous measurement result and the current measurement result to the reference value of each asymmetric rotor, the reference of the plurality of types of asymmetric rotors whose imbalance should be measured A method for adjusting a balance testing machine, wherein each value is corrected. The method of adjusting a balance testing machine according to claim 1, wherein the correction master rotor is made of any one of the plurality of types of asymmetric rotors whose unbalance should be measured. The method of adjusting a balance testing machine according to claim 1 or 2, wherein the unbalance distribution in the correction master rotor is a predetermined state.

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