JPH0462411A - Inspecting method for pressing-in state - Google Patents

Abstract

PURPOSE:To improve the reliability of the inspection of the pressing-in state by inspecting the pressing-in state from not only the maximum load at the time of pressing-in operation, but also the pressing-in distance and the energy quantity required for the pressing-in operation, i.e., three variables. CONSTITUTION:A load cell 1 measures a pressing-in load A placed on a pressed-in body and a distance sensor 2 measures the pressing-in distance B. Then electric signals indicating the pressing-in load A and pressing-in distance B are supplied to a computer 7 through amplifiers 3 and 4 and A/D converters 5 and 6. The computer 7 calculates the pressing-in energy quantity C from the measured values of the pressing-in load A and pressing-in distance B. Then the comparing function 8 in the computer 7 compares the maximum load A1, pressing-in distance B1, and total energy quantity C1 required for the pressing-in operation from the start to the end with desired standard ranges of the respective variables. At this time, only when the measured values A1, B1, and C1 are all within the standard ranges, it is judged that the pressing-in state is 'proper'.

Description

Detailed Description of the Invention =Object of the Invention= [Industrial Field of Application] The present invention is directed to a method for inserting a relatively small press-fit object such as a pin into a plate, pipe rod, etc. that has a hole provided for the purpose of press-fitting it. The present invention relates to a press-fitting state inspection method for determining whether or not the press-fitted object is normally press-fitted when the press-fitted object is press-fitted.

[Conventional technology]

Conventionally, the method of determining whether or not the press-fitted object has been properly press-fitted into the hole provided inside the pressurized interior is to measure the press-fitting load at the time of press-fitting with a load measuring device such as a load cell, and to measure the press-fitting load from the start of press-fitting to the end of press-fitting. Press-fit maximum load 10 indicating its peak value in per hour
A1 or the desired standard range set in advance (10Arn1
The suitability of the press-fitting state was determined based on whether the condition was within n<10A+<10Amax).

As shown in FIG. 9, which explains the principle with a block diagram as an example of a conventional press-fitting state inspection method, the press-fitting state inspection device measures the press-fitting load applied to the press-fitted object and determines whether the press-fitting state is appropriate or not. A function is provided to determine the Specifically, a load cell 101 is attached to the press-fitting device and measures the load during press-fitting as the amount of strain. An amplifier H1oa that amplifies the amount of strain in the load cell 101, an A/D converter 1105° that converts an analog signal into a digital signal, and a comparison device 10 that determines whether the press-fitting state of the press-fit object is normal or abnormal.
It was equipped with a signal processing function such as 8.

[Problems to be solved by the invention]

However, due to the above inspection method, the maximum load during press-fitting is 1
Even though 0A1 satisfies the standard range,
During transportation or use of the product, problems may occur, such as the fit of the press-fitted object loosening in the hole of the press-fitted object, or in the worst case, the press-fitted object falling off.

In other words, even if the maximum load during press-fitting (10 A) is within the standard range, the actual length of the press-fitting object (such as a pin) or the hole of the press-fitted object, the so-called press-fitting distance. It is conceivable that some parts are not suitable, and the fitting length (press-fit distance) is not sufficient, causing problems such as falling off.

Therefore, according to the conventional method, there was a problem in quality reliability and certainty as a method for evaluating the press-fit state.

=Structure of the Invention= [Means for Solving the Problems] 1. Press-fitting to determine whether or not the press-fit object has been properly press-fitted when press-fitting the press-fit object, such as a pin, into a hole provided in the press-fit object. In the condition inspection method, the measured values of three variables, the maximum press-fitting load and press-fitting distance from the start of press-fitting to the end of press-fitting, and the amount of press-fitting energy indicating the energy required for press-fitting, are within the desired standard range for each variable. The suitability of the press-fitting state of the press-fitted object is determined by whether or not the press-fitting material is present.

2. Compare the measured values of the three variables, the maximum press-fitting load and press-fitting distance from the start of press-fitting to the end of press-fitting, and the amount of press-fitting energy indicating the energy required for press-fitting, with the desired standard range of each variable. A figure is displayed on the screen of the display device, and an appropriateness judgment based on whether the press-fitting state is appropriate or not is displayed on the screen.

[Examples and effects]

Embodiments of the present invention will be described below based on the drawings.

FIG. 6 is an explanatory view of the main parts of the press-fitting device 15 based on the embodiment of the present invention, in which 20 is a hollow tube as an object to be press-fitted, and 22 is a hole for press-fitting provided in the hollow tube 20. , 21 indicate fitting pins as press-fit objects.

FIGS. 2 and 3 are enlarged views of part M in FIG. Figure 3 shows the press-fitting completed state.

A press-fitting device 15 for applying a predetermined press-fitting load to the press-fitting object 21 and press-fitting the press-fitting object 21 into the hole 22 includes a press-fitting device 15 that presses the press-fitting object 21 into the hole 22 by applying a predetermined press-fitting load to the press-fitting object 21.
In addition to the press-fit terminal 17 that presses the press-fit terminal 1, there is a load cell that is connected to the press-fit terminal 17 and measures the press-fit load applied to the press-fit terminal 17. A distance sensor 2 for measuring the press-fitting distance is also attached.

A strain gauge (not shown) is installed in the load cell 1, and the press-fitting load A is measured as the amount of strain on the strain gauge. The distance sensor 2 also has a measurement terminal 1 supported movably in the axial direction by a spring (not shown).
8, and the measurement terminal 18 is provided to face a mechanism 16 that interlocks with the load cell 1, and a change in the relative position in the axial direction of the press-fit terminal 17 provided at the tip of the load cell 1 is caused by the interlocking mechanism 16. 16 to the measuring terminal 18 of the distance sensor 2, and the fitting length between the press-fit object and the press-fit object, that is, the press-fit distance B is measured.

FIG. 1 is a diagram illustrating the principle of a press-fitting state inspection method according to an embodiment of the present invention. The press-fitting device 15 is equipped with a signal processing function that determines the suitability of the press-fitting state after measuring the load A and press-fitting distance B during press-fitting, and a function that graphically displays the press-fitting state together with the suitability determination.

Specifically, first, a load cell 1 that is attached to the press-fitting device 15 measures a press-fitting load A, a distance sensor 2 that measures a press-fitting distance B, an amplifier 3 that amplifies the electrical signals in the load cell 1 and the distance sensor 2, 4. A/D conversion mixer 5, 6 for converting analog signals into digital signals, and 2.
A calculation function that calculates the press-fitting energy amount C based on the variables A and B.

It also includes a computer 7 having a function 8 for comparing measured values and standard ranges, and a display device 9 for displaying the inspection results of the press-fit condition.

The computer 7 has an arithmetic function to calculate the press-fitting energy amount C from the measured values of the press-fitting load A and the press-fitting distance B. That is, as shown in Fig. 8, when the press-fit distance A is d and the curve showing the change in press-fit load B is f (x), the press-fit energy amount C is calculated by the general formula W = f', f (x) dx Calculated by Further, based on each of the above-mentioned measured values, the maximum load AI during press-fitting and the press-fitting distance Bl are determined.

A comparison function that extracts the three variables of the press-in energy amount C1 as the three variables for which the press-fit state should be evaluated, and determines whether the press-fit state of the press-fit object is appropriate by comparing with the desired standard range of each variable set in advance. 8 is provided in the computer 7.

A display device 9 such as a cathode ray tube displays a display screen 11 as shown in FIG. 4 and FIG. have

Next, a method for inspecting a press-fit state according to the present invention will be explained.

First, the press-fitting object 20 having a hole 22 provided for the purpose of press-fitting is placed in the press-fitting device 15, as shown in FIG.
are set facing each other.

Next, after positioning the press-fit object 21 such as a pin with respect to the hole 22 as shown in FIG. A press-fit material 21 is press-fitted into the hole 22 . As shown in FIG. 3 when the press-fit is completed, the press-fit object 21 is press-fitted into the hole 22 by a distance indicated by the fitting length B, compared to the press-fit start state shown by the two-dot chain line. .

As described above, the press-fitted object 21 is replaced with the press-fitted object 2 having the hole 22.
As shown in FIG. 1, as a method for inspecting the press-fitting condition when press-fitting with respect to At the same time, the distance sensor 2 similarly attached to the press-fitting device 15 detects the distance between the press-fit object 21 and the hole 22.
The fitting length in the axial direction, that is, the press-fitting distance B is measured.

Next, the electrical signals indicating the press-fitting load A and the press-fitting distance B obtained by the load cell 1 and the distance sensor 2 are converted into digital signals by passing through the amplification circuits 3 and 4 and the A/D conversion circuits 5 and 6, respectively. The data is converted into data and supplied to the computer 7.

In the computer 7, the amount of press-fitting energy C is calculated from the measured values of the press-fitting load A and the press-fitting distance B using its calculation function. Similarly, the comparison function 8 set in the computer 7 by a program or the like determines the three variables to be inspected for the press-fitting condition, namely, the maximum load A1 from the start of press-fitting to the end of press-fitting, and the press-fitting distance B] and the press-fitting condition. The required total amount of energy C1 is compared with the desired standard range of each variable. At this time, it is compared whether each measured value A l+ B + + C+ is within the range indicated by the minimum value and maximum value of each standard range, and the measured value Al of the three variables is
Only when +BI C'l are all within the standard range as shown below, is the press-fitting condition determined to be "suitable".

A m1n(A I < A max B m1n(B ] (B max −) OK
Cm1n(C1<Cmax Figures 7 (a), (b) and (c) show the results of measuring the relationship between the shearing load of the press-fitted object against the press-fitted object and the three variables mentioned above regarding press-fitting.In particular, (b) ) shows a strong positive correlation between the amount of press-in energy and the pull-out load, and compared to the conventional method of inspecting only the maximum press-in load,
Since the press-fit condition is inspected using each of the three variables, the press-fit condition can be grasped more accurately.

The data via the computer 7 is sent to the display device 9, and as shown in FIGS. 4 and 5 on the display screen 11, the suitability of the press-fit state is determined 12, and the press-fit state is graphically displayed 1.
3. The measurement results of the 3 variables are displayed.

The graphical display 13 is, for example, a radar chart-like graphic with each variable as its axis, and the press-fitting state can be visually grasped by the display graphic 13.

As an example of the display method, Fig. 4 shows that the press-fit condition is "OK" (suitable) because each measurement value is within each standard value range, and Fig. 5 shows that the press-fit condition is "OK" (suitable). Minimum specification value B
The press-fit condition is “NG” (unsuitable) because it is less than min.
A suitability determination display 12 is made for each.

Therefore, according to the present invention, the press-fitting condition is inspected not only by the maximum load at the time of press-fitting, but also by the three variables of the press-fitting distance and the amount of energy required for press-fitting. Condition can be quantitatively evaluated. Also,
By instantly displaying the press-fit condition graphically on the screen,
The press-fit condition can also be qualitatively evaluated.

=Effects of the Invention= As described above, according to the present invention, the press-fit condition is inspected not only by the maximum load at the time of press-fitting, but also by the three variables of the press-fit distance and the amount of energy required for press-fit, so that the press-fit condition can be accurately grasped. In addition to improving the properties, the press-fit condition can be quantitatively evaluated. Further, since the press-fitting state is immediately graphically displayed on the screen, the press-fitting state can be qualitatively evaluated as a pattern. Therefore, it is possible to improve reliability in inspecting the press-fit state and to provide an inspection method with excellent man-machine interface.

[Brief explanation of drawings]

1 to 8 represent embodiments of the present invention.
The figure is an explanatory diagram of the principle of the press-fit condition inspection method, Figures 2 and 3 are partial cross-sectional plan views showing the press-fit process, and Figures 4 and 5 are the displays of the press-fit results shown on the screen of the display device. FIG. 6 is an explanatory diagram of the main parts of the press-fitting device, FIG. 7 is a graph showing the relationship between each variable and the shearing load, and FIG. 8 is a graph showing the relationship between the press-fitting distance and the press-fitting load. FIG. 9 is an explanatory diagram of the principle of a conventional press-fitting state inspection method. (Explanation of symbols) 1- e load cell. 2II ・Distance sensor. 7. ・Combiner Niichiyo. 8. - Comparison function. 9 ・ 12 ・ 21 ・ A ・ C fist A1 ・ B1 ・ C1 ・ Display device.・Suitability judgment display.・Pressed items.・Press-fitting load.・Amount of press-fitting energy.・Measurement value of maximum press-fitting load.・Measurement value of press-fit distance.・Measurement value of press-fit energy amount. · ·screen. - Pressurized items.・・Hole.・Press-fitting distance. 20 Middle B fist

Claims (1)

[Claims] 1. In a press-fitting state inspection method for determining whether or not the press-fitting object is normally press-fitted when a press-fitting object such as a pin is press-fitted into a hole provided in a press-fitting object, Maximum press-fitting load A_1 and press-fitting distance B_1 from time to end of press-fitting, and press-fitting energy amount C_1 indicating the energy required for press-fitting.
A method for inspecting a press-fitting state in which the suitability of the press-fitting state of a press-fit object 21 is determined based on whether the measured value of a variable is within a desired standard range for each variable. 2. Maximum press-fitting load A_ from the start of press-fitting to the end of press-fitting
Measured values A_1, B of three variables: 1, press-fit distance B_1, and press-fit energy amount C_1 indicating the energy required for press-fit.
_1, C_1 and the desired standard range of each variable are displayed as a graphic display 13 on the screen 11 of the display device 9, and a suitability judgment 12 for judging the suitability of the press-fitting state is displayed on the screen 11. A press-fitting state inspection method according to claim 1.