JPH0521495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is used in the field of unbalance measurement of structures.

The present invention relates to a method and apparatus for measuring unbalance, and more particularly to a method and apparatus for measuring unbalance in a propeller shaft for an automobile, in which a test object has a plurality of correction surfaces, for example.

(b) Prior art In recent years, in order to increase the speed of automobiles and improve the reliability of products, especially to reduce vibration and noise at high speeds, conventional 2-joint 1-piece or 3-joint 2
The use of four-joint, three-piece propeller shafts has shifted from one-piece propeller shafts.

In order to measure and correct the unbalance of this 4-joint, 3-piece propeller shaft, as shown in Figure 3, select six locations on both ends of each piece as correction surfaces, and use these correction surfaces to measure and correct the unbalance. However, it is possible to approximate the correction by selecting four of these six correction surfaces as correction surfaces, measuring and correcting them, and theoretically and efficiently. known from experience.

(c) Problems to be Solved by the Invention In the prior art, these four correction planes are selected in advance, and the unbalance is measured and corrected. When such pre-selected, measured, and corrected values are used, the amount of correction often becomes extremely large, and there are cases where there is no correction weight that can handle it. Even if a heavy correction weight is used, if the initial unbalance is large, a large residual unbalance will remain due to the correction error.
Distortion may occur due to welding during installation, and excessive internal stress may occur in the propeller shaft body due to the installation of heavy weights at the poles, which may lead to breakage.

Therefore, in such a case, changing the relative positions of the parts of the propeller shaft, reassembling the propeller shaft, and performing the balancing operation again requires a large amount of man-hours and time, and is an unreasonable task.

The purpose of the present invention is to eliminate these problems by detecting unbalance, monitoring the amount of unbalance at each correction surface from among, for example, six correction surfaces of the propeller shaft, and setting the amount according to its characteristics. To provide a method and a device for selecting at most four correction surfaces and determining the amount of unbalance, which can be corrected most accurately and efficiently according to the conditions and distribution state of unbalance.

(d) Means for solving the problem The above purpose is to calculate all the corrections necessary for correction from all correctable correction surfaces in an unbalance measurement method for balancing a rotating body having a plurality of correction surfaces. A smaller number of correction surfaces than the number of surfaces is selected as a set, the unbalance on each correction surface belonging to the group is calculated based on the input value of the unbalance signal from the vibration detector, and then the same number of correction surfaces are corrected from all correction surfaces. Select the surface as another set, calculate the imbalance in each corrected surface belonging to that group in the same way, and then similarly calculate the imbalance in each corrected surface belonging to each group for an appropriate number of groups, and Conditions set in advance for correcting the unbalance of the rotating body are input, one set is selected from an appropriate number of sets by comparison with the conditions, and each correction surface belonging to that set and the unbalance therein are selected. By outputting the The calculation device includes a setting device for inputting optimum conditions into the calculation device, and a display device for displaying unbalance, and the calculation device is configured to input a plurality of sets of combinations of correction surfaces necessary for correcting the imbalance of the rotating body. It has a memory section for storing imbalances in each of the correction planes belonging to each, and has calculation means for comparing these imbalances with the setting conditions and selecting one set from an appropriate number of sets. This can be achieved by outputting the corrected plane and imbalance of the set to the display means.

(e) Action: Select, for example, 4 sets with different combinations from among all the correctable faces that are smaller than the number of all the correctable faces required for correction, and then select 1 set from the 4 sets. At this time, conditions are added, and by comparison with the conditions, a set that most closely matches the conditions is selected, thereby streamlining the subsequent unbalance correction work.

(F) Embodiment A preferred embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, as an example of a test object, 4 joints 3
A schematic structure of a piece propeller shaft is illustrated in FIG. A, B, and C are pipes or shafts that transmit driving force, and are connected by freely swingable joints a, b, c, and d, and their ends D and E form a propeller shaft 10.

As shown in FIG. 4, four locations, end D, center support bearings J and K, and end E, are supported by vibration detection sections 11 to 14 of a dynamic balance tester to detect unbalance.

As explained using a conventional example, the balance of such a 4-joint 3-piece propeller shaft 10 is achieved by selecting four correction planes from among the correction planes shown in FIG. The unbalance of the entire propeller shaft 10 is calculated, and the amount and angle of unbalance to be corrected are displayed.

FIG. 5 shows the main parts of a conventional unbalance measurement and correction device. Vibration detector 11 of the vibration detection section
The unbalance signal detected in steps 14 to 14 is introduced into a calculation device 15 disposed in a measuring device (not shown), and four correction planes selected in advance within the calculation device 15 are input.
For example, the unbalance in the correction planes, . . . is calculated, and the display devices 21-
The imbalance is displayed in 24.

Unbalance is usually expressed in terms of angle and amount of unbalance. The amount of unbalance may also be displayed as a correction weight prepared in stages. A weight is welded to each of the four correction surfaces by a welding machine (not shown) according to the amount of unbalance displayed on each display device. However, as described above, problems occur, such as an extremely large weight being displayed for certain correction surfaces.

Embodiments of the invention are described with respect to FIGS. 1 and 2. FIG. The unbalance signals from the detectors 11, 12, 13, 14 are introduced into the arithmetic unit 115,
In the arithmetic unit 115, an unbalance correction surface is selected in response to a command from a setting device 116 that specifies calculation conditions to be described later, and the unbalance on the selected correction surface is calculated. The calculation conditions commanded by the setting device 116 are determined by the characteristics of the propeller shaft, and for example, limit the maximum value of each correction weight of the four correction surfaces and minimize the total weight of each correction weight. If this is the condition, the calculation is performed in the arithmetic unit according to the following procedure. Correction side,
, , are selected as a set and calculated, and the unbalance results (quantities, angles) are stored. Next, select and calculate other sets of , , and store the results.

In this way, four sets (for example, , , and ) are sequentially selected and calculated from the correction plane ~, the results are stored in the memory section for each set, and these are read out and calculated under the calculation conditions. The most suitable combination of correction surfaces is selected after comparison and examination. The corrected planes and unbalances belonging to the selected group are displayed on display devices 121-126. When the correction plane 1 is selected, the amount of unbalance is displayed on the display device 121 corresponding to the correction plane 1. The unbalance amounts for the other selected correction planes are also displayed on the corresponding display devices 122 to 126, respectively. The display devices 121 to 126 display the angle and amount of unbalance, but if an angle positioning device for positioning the unbalance angle to the welding position is attached, the unbalance amount or unbalance correction weight is selected and displayed. Sometimes.

FIG. 2 is a diagram illustrating a case where there are four unbalance display devices. In addition to the functions of the display devices described above, the display devices 221 to 224 have a function of additionally displaying a symbol indicating the position of the selected correction plane. A correction surface positioning device for positioning the welding machine on a selected correction surface can also be attached, and in this case, the function of displaying the correction surface position can be omitted.

Depending on the conditions required by the characteristics of the propeller shaft, the optimum four correction surfaces are selected from among the six correction surfaces, the unbalance is displayed, the unbalance is corrected according to this, and the propeller shaft is adjusted. The purpose of this is to enable the system to operate in its best condition.

The number of correction surfaces is basically six, but depending on the shape and characteristics of the propeller shaft, for example, if one pipe is extremely short, the number of correction surfaces may be five.

The calculation conditions include setting a limit for the amount of correction in one correction surface, minimizing the total weight of correction weights for each correction surface, and setting a correction surface in which the amount of correction in at least one correction surface is less than the allowable value. If a selection occurs, it may be possible to give priority to this selection.

(g) Effects According to the present invention, residual unbalance can be reduced most efficiently by setting conditions, the balancing work can be shortened, and the balance quality of the propeller shaft can be improved. Furthermore, by setting a limit on the amount of correction for one correction surface,
The mechanical strength of the propeller shaft can be ensured, and the total weight of the correction weight can be minimized, thereby reducing material costs. In addition, if the amount of correction on the correction surface is within the allowable value, welding work for correction can be omitted.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of main parts showing one embodiment of the present invention, FIG. 2 is a diagram similar to FIG. 1 showing another embodiment,
FIG. 3 is a diagram illustrating the configuration of the propeller shaft, FIG. 4 is a diagram illustrating the arrangement of the propeller shaft, vibration detector, etc., and FIG. 5 is a diagram similar to FIG. 1 of the conventional example. 10 is a propeller shaft, 11 to 14 are vibration detectors, 15 is a conventional arithmetic unit, 21 to 24 are conventional display devices, 115 and 215 are arithmetic units according to the present invention, and 121 to 126 and 221 to 224 are main units. The display devices 116 and 216 according to the invention are calculation condition setting devices.

Claims (1)

[Scope of Claims] 1. In an unbalance measurement method for balancing a rotating body having a plurality of correction surfaces, a number of correction surfaces smaller than the number of all correction surfaces necessary for correction from all correction surfaces that can be corrected. is selected as a set, and the unbalance on each corrected surface belonging to that group is calculated based on the input value of the unbalance signal from the vibration detector.Then, the same number of corrected surfaces are selected from all the corrected surfaces as another group, and the The unbalance on each corrected surface belonging to the group is calculated in the same way, and the unbalance on each corrected surface belonging to each group is similarly calculated for an appropriate number of groups, and on the other hand, for the unbalance correction of the rotating body. A preset condition is input to the system, one set is selected from an appropriate number of sets by comparison with the condition, and each corrected surface belonging to that set and the imbalance among them are output. , unbalance measurement method. 2. In an unbalance measuring device for balancing a rotating body having multiple correction surfaces, a vibration detector for detecting unbalance and an arithmetic device that receives signals from the vibration detector and calculates the unbalance. , a setting device for inputting optimal conditions according to the characteristics of the rotating body into the calculation device, and a display device for displaying the unbalance, and the calculation device has a setting device for inputting optimal conditions according to the characteristics of the rotating body into the calculation device, and a display device for displaying the unbalance. It has a memory section that stores the imbalance in each correction surface belonging to each of a plurality of combinations of correction surfaces, and also selects one group from an appropriate number of combinations by comparing these imbalances with the setting conditions. 1. An unbalance measuring device, comprising a calculation means for selecting a corrected surface and an unbalance of the set, and outputs the corrected surface and unbalance of the set to a display means.