JPH03205505A - Transverse section area measuring instrument - Google Patents

Abstract

PURPOSE:To measure the transverse section area of each part of an object to be measured without destruction by dipping the object to be measured in the liquid in a container to optional length and putting the object in and out of the liquid finely in its length direction as a vertical direction, and measuring the specific gravity of the liquid, the dipping length, and the apparent weight of the object. CONSTITUTION:When one end part of a crank shaft 1 is gripped with a gripper 10 to rotate a handle 9, the crank shaft 1 is dipped in the liquid 4 filling the container 3 up to its upper end in the length direction as the vertical direction. The dipping length is detected by a rotary encoder 12 and inputted to a CPU 14 through an interface 13. Further, the apparent weight of the crank shaft 1 dipped in the liquid 4 is measured by a load cell 11 in a buoyance presence state and inputted to the CPU 11. A guide rod 6 is moved down continuously and the ratio of the quantity of variation in the apparent weight of the crank shaft 1 to the quantity of variation in downward movement length is found to find the transverse section area of each part of the crank shaft 1 and, therefore, its distribution.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is applicable to products manufactured by forging, cutting, etc.
The present invention relates to a cross-sectional area measuring device suitable for non-destructively determining the dimensions and volume distribution of a model that corresponds to the product, that is, has substantially the same dimensions and shape as the product.

(Conventional technology) When manufacturing products by forging whose transverse cross-sectional area (cross-sectional area) varies greatly depending on the longitudinal position, it is usually necessary to prevent the occurrence of underfilling and deterioration of material yield due to excessive deburring. In order to achieve this, the volume of the forged material is distributed in the longitudinal direction in correspondence with the longitudinal volume distribution (cross-sectional area distribution) of the product.

For example, when forging a crankshaft as shown in FIG. 5(c), which is one of the products mentioned above, first, a square bar-shaped material is forged in the longitudinal direction of the crankshaft as shown in FIG. 5(a). The volume is distributed in the longitudinal direction by rolls or shapes in accordance with the volume distribution, and then, as shown in FIG. Thereafter, the raw material is fed into a forging die and is forged into a crankshaft having a predetermined size and shape, as shown in FIG. 3(c).

Conventionally, when performing the volume distribution of the forged material described above, as shown in FIG. Based on the cross-sectional area determined from the shape, the cross-sectional area and length of each part with different cross-sectional areas are calculated from the cross-sectional line diagram, the volume of that part is calculated, and the volume of that part is calculated based on those volumes. The method used was to determine the volume distribution in the longitudinal direction of the material.

Furthermore, when manufacturing the drive shaft 21 shown in FIG. 7, which is one of the axially symmetrical products, by forging, cutting, etc., conventionally, the manufactured product is usually divided into a shaft portion 21a,
For the radial dimensions of 2lb and 21c, use a measuring instrument such as a caliper as shown by the arrow in the same figure, and for the position of the part where the radial dimension changes, such as a part of the taper, as shown in Figure 8. Dimensional inspection of products has been carried out by manually measuring each product using a gauge 22, or by automatically measuring using an optical measuring device or the like that scans the product with a laser beam.

(Problem to be Solved by the Invention) However, in the former case where the volume distribution of the forged product is sought, since the forged product is usually provided with draft angles, chamfered corners, curved surfaces, etc. in each part, It is extremely difficult to accurately determine the cross-sectional area from the drawing dimensions and shape of the product, and for this reason, it has not been possible to adequately distribute the volume of the material in the past.

In order to solve this problem, a forging model with the dimensions and shape suitable for the product can be created by test-driving the steel material using a forging die, or by shaping and cutting the soft material based on the dimensions and shape of the drawing. It is also possible to directly obtain the cross-sectional area of each part by cutting the model for forging, but conventionally, when the product shape is complex, the cross-sectional area in the longitudinal direction, which is the volume distribution, There was no suitable method for determining area distribution.

In addition, in the latter case of measuring the dimensions of manufactured axially symmetrical products, there is a problem in that manual inspection requires a lot of man-hours and can only be carried out by sampling, and since it is done visually, there are individual differences. If a measuring device is used, there are problems in that the device is expensive, the inspection cost increases, and the measurable range is severely restricted.

In order to solve this problem, since the object to be measured here is an axially symmetrical product, it is sufficient to have an appropriate device that can non-destructively measure the axial distribution of the cross-sectional area.

The present invention provides a cross-sectional area measuring device that advantageously solves this problem.

(Means for Solving the Problems) A cross-sectional area measuring device of the present invention includes a container for storing a liquid of a predetermined specific gravity, and a measuring object placed in the liquid in the container with its longitudinal direction being perpendicular. an intrusion length measuring means for measuring the length of penetration of the measurement object into the liquid in the container, and an apparent weight of the liquid in the container or an apparent weight measuring means for measuring the apparent weight of the object to be measured that has entered the object; The apparatus is characterized by comprising a cross-sectional area calculation means for calculating the cross-sectional area near the liquid surface.

(Operation) If the object to be measured is immersed in the liquid in the container for an arbitrary length with its longitudinal direction perpendicular to the liquid surface, and then inserted or pulled out from that position by a minute distance from the liquid surface, the object to be measured will be The buoyant force applied to the object to be measured changes by the amount of change in the volume of the object immersed in the liquid multiplied by the specific gravity of the liquid. The apparent weight of each changes.

Therefore, if the minute length of the object to be measured relative to the liquid level, the amount of change in the apparent weight of the liquid or the object to be measured, and the specific gravity of the liquid are known, the cross-sectional area of the object to be measured near the liquid surface can be determined.

Based on this principle, here, the means for inputting and outputting the object to be measured is
The object to be measured is immersed into or withdrawn from the liquid in the container with its longitudinal direction vertically, and during this time, the immersion length measuring means measures the immersion length of the object to be measured into the liquid. At the same time, the weight measuring means measures the apparent weight of the liquid or the object to be measured, and from these measurement results and the specific gravity of the liquid determined in advance, the cross-sectional area calculation means calculates each part of the object to be measured. Calculate the cross-sectional area of

Therefore, according to the device of this invention, the cross-sectional area distribution of the object to be measured can be automatically and non-destructively measured with a simple device and with high precision. The volume distribution of the forged material can be determined with high precision, and the volume distribution of the forged material can be made sufficiently good.
If this device is applied to an axially symmetrical product, the dimensions of each part of the product can be measured and inspected over a wide measurable range at low cost and with high precision.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the structure of an embodiment in which the cross-sectional area measuring device of the present invention is used for measuring a forging model.
3 indicates a frame, and 3 indicates a container, in which a liquid 4 having a predetermined specific gravity, such as water, is stored.

In addition, 5 in the figure shows a screw-type lifting mechanism as a means for taking in and out the measurement object, and this lifting mechanism 5 has a substrate 7 fixed to the lower ends of two guide rods 6 that are supported by the frame 2 so as to be able to move up and down. At the same time, the lower end of a screw shaft 8 screwed into the frame 2 is pivotally supported by the base plate 7, a handle 9 is screwed into the upper part of the frame 2 of the screw shaft 8, and further,
A gripper 10 is provided on the lower side of the substrate 7 and is capable of gripping a forging model as an object to be measured.

A load cell 11 is inserted between the gripper 10 and the substrate 7 as an apparent weight measuring means that can measure the load applied to the gripper 10. Rack 6 installed in
A rotary encoder 12 is installed as means for measuring the penetration length and has a pinion 12a meshing with the load sensor 11 and the rotary encoder 12, which are connected to the central processing unit as means for calculating the cross-sectional area via an interface 13. (CPU) 14, and (7) CPU 4 is further connected to a display device 15 that displays input characters, etc. as an image, and a printer 16, which prints input characters, etc. on paper. .

In such a cross-sectional area measuring device, for example, a steel material is test-shot using a forging die, and a crankshaft (which is the same as the product, so it is (indicated by code 1).
By gripping one end of the crankshaft 1 with the gripper 10 and manually rotating the handle 9 in a predetermined direction, the container 3 is filled with liquid to the top, as shown in FIG. 2(a), for example. When the crankshaft 1 is inserted into the liquid 4 as shown by the arrow in the figure with its longitudinal direction being vertical, the rotary encoder 12 measures the penetration length of the crankshaft 1 into the liquid 4 using the guide rod 6. A signal indicating the penetration length is measured from the descending length of the liquid 4 and is inputted to the cpul 4 via the interface 13. At the same time, the load cell 11 detects the buoyant force of the crankshaft 1 penetrating into the liquid 4. The apparent weight of
A signal indicating the apparent weight measured from the load applied to the gripper 10 is sent to cpul4 via interface l3.
Enter.

In this case, since the liquid 4 is filled up to the top of the container 3 from the beginning, the liquid 4 removed by the infiltration of the crankshaft 1 spills out from the top of the container 3, and as a result, The height of the liquid level is always kept constant, and the descending length of the guide rod 6 remains the same.
This is the penetration length of the crankshaft.

From these input signals, CPU 4 calculates the cross-sectional area of crankshaft 1 as follows.

In other words, the descending length of the guide rod 6 from the position where the lower end surface of the crankshaft 1 and the liquid level are the same height is defined as
, apparent Il amount of crankshaft 1 wo f (x),
The original weight of the crankshaft l is W, and the total volume of the crankshaft 1 is ■. , the total length of crankshaft 1 is L
1 The volume of the intrusion of crankshaft 1 into liquid 4 is V
(x), crankshaft} 1 density is σ1, liquid 4 density is σ, (however, W, = f (0), V (0)
= 0, σ. ='W, /Vi, ■iV (L). ), the above f (x) becomes f(x) = {
Vm V(x)) σw=+V(x)(σm−σ,)
=σ,・■,−σ,・V (x) =W. 1σ,・V (x) 1・−(
1), and when both sides are differentiated by X'''rc, we get:

Therefore, the cross-sectional area S (x) of the crankshaft 1 near the liquid level is as follows. Since the density σ1 of the liquid 4 is known in advance, for example, while lowering the guide rod 6 intermittently, each time it stops, By determining the descending length from the previous stop position and the amount of apparent weight reduction from the previous stop from the input signal, or, for example, by continuously lowering the guide rod 6, the amount of decrease is constant based on the input signal. By determining the amount of decrease in the apparent weight each time the guide rod 6 descends, the ratio of the amount of change df (x) in the apparent weight f (x) of the crankshaft 1 to the amount of change dx in the descending length X of the guide rod 6 is determined. Once calculated, by substituting it into the above equation (2), the cross-sectional area S (x) of each part of the crankshaft 1, and thus the cross-sectional area distribution, can be calculated.

Further, as shown in FIG. 2(b), for example, the crankshaft 1 is placed in the liquid 4 filled to the middle of the container 3 in the same manner as described above, as shown by the arrow in the figure, with the elongated direction being the vertical direction. In this case, the liquid 4 removed by the intrusion of the crankshaft 1 is transferred from the upper end of the container 3 to the outside. Since the height of the liquid is raised instead of spilling into the liquid 4, the descending length Amount of change dx in the descending length X of the rod 6
The change amount duO ratio of the penetration length U of the crankshaft l into the liquid 4 relative to the liquid 4 can be determined.

That is, when the descending length of the guide rod 6 from the position where the lower end surface of the crankshaft 1 and the initial liquid level are at the same height is X, the length of penetration of the crankshaft 1 into the liquid 4 whose liquid level has risen. U, fluid 4 on crankshaft 1
Let V (u) be the volume of the infiltration into the container 3, and Sc be the cross-sectional area inside the container 3. Similarly to (1) 2, f (x) = Wn - σL H V (u)
-- (3), and when both sides are differentiated by X, we get:

On the other hand, if the initial depth of the liquid 4 without the crankshaft 1 is H, then the sum of the total volume of the liquid (H-se) and the above volume V (u) is the entire area below the raised liquid level. Since it is a product, H-Sc+V(u)=((u-x)+H)Sc, therefore, V(u)=Sc(ux), and when both sides are differentiated by X, it becomes.

Substituting equation (4) into equation (5), we get Then, Therefore, becomes.

By the way, the cross-sectional area S (u) of the crankshaft 1 near the liquid level is S (・) Ikki (9) = S. (1--!!-!l!-)
1 < 7) du du yell.

Substituting equation (6) into equation (7), we get S(・>=Sc
＜11'' Once red value 11) σt ・Sc df(x)/
dx, 1 S (u) 1(- − − ) − '
- (8) Sc df(x)/dx Therefore, since the density σ of the liquid 4 and the cross-sectional area SC inside the container 3 are known in advance, the guide rod is If the ratio of the change amount df (x) in the apparent weight 1f(x) of the crankshaft 1 to the change amount dx in the descending length Thus, the cross-sectional area S (u) of each part of the crankshaft 1, and thus the cross-sectional area distribution, are determined.

Then, the CPU 4 outputs the cross-sectional area distribution of the crankshaft 1 calculated by the calculation as described above as an image or printout using the display device 15 or the printer 6.

Therefore, according to the apparatus of this embodiment, the cross-sectional area distribution of the crankshaft 1 as a forging model can be easily and accurately measured, so that the volume distribution in the longitudinal direction of the crankshaft 1 can be determined with high precision. This makes it possible to achieve a sufficiently good volume distribution of the material.

According to the apparatus of the above embodiment, the volume of each part of the forging model having a different cross-sectional area can be directly determined from the descending length of that part and the amount of change in apparent weight. Even in this way, the volume distribution can be determined more accurately than before.

FIG. 3 is a structural diagram showing another embodiment in which the cross-sectional area measuring device of the present invention is suitable for measuring axially symmetrical products.
3 indicates a container, and this container 23 contains, for example, water, etc.
A liquid 24 having a predetermined specific gravity is stored.

In addition, 25 in the figure shows a Cartesian coordinate type robot as means for inputting and outputting the object to be measured. The gripper 27 grips and releases the drive shaft 21, which is an axially symmetrical product to be measured.
7 and the drive shaft 21 held there.
can be added to and removed from the liquid 24 in the container 23.

On the other hand, 28 in the figure shows a precision spring scale as an apparent weight measuring means, and the container 23 is the stand 28 of the precision spring scale 28.
This precision spring scale 28 supports the container 23 by pushing up the stand 28a with the reaction force of the built-in spring, and uses the built-in encoder to calculate the above value based on the apparent weight of the container 23 and the liquid 24. Platform 2 based on spring deflection
The amount of descent of 8a can be detected and output as a signal.

The output signal of the precision spring scale 28 is input to a signal conversion control device 29 that includes a normal microcomputer, and this signal conversion control device 29 calculates the output signal of the precision spring scale 28 to determine the amount of data in the container 23. Converting the apparent weight of the liquid 24 into an increment, displaying the value on the display device 28b of the precision spring scale 28, and using a signal indicating the value and a signal indicating the amount of descent of the platform 28a as a cross-sectional area calculation means. output to a normal personal computer 30.

In addition to the output signal of the signal conversion control device 29, the personal computer 30 here also determines the position of the drive shaft 21 gripped by the gripper 27, which is output by the robot control device 26 based on the output signal of the rotary encoder built in the robot 25. Input the signal indicating
Further, calculation results based on these input signals are outputted by a display device 31 or a printer (not shown).

In such a cross-sectional area measuring device, based on the operation of the robot 25, one end of the drive shaft 21 manufactured by forging, for example, is gripped by the gripper 27, and first, as shown in FIG. The drive shaft 21 is moved to a position where the liquid level of the liquid 24 and the lower end of the drive shaft 21 are at the same height, and then the drive shaft 21 is placed in the liquid 24 in the longitudinal direction of the keyaki shown by the arrow in the figure. When a certain axial direction is set as a vertical direction, the personal computer 30 outputs the drive shaft 21 to the liquid 24 shown in FIG. In addition to sequentially inputting a signal indicating the descending length X of and a signal indicating the amount of descent y of the platform 28a are inputted sequentially.

From these input signals, the personal computer 30 calculates the cross-sectional area of the drive shaft 21 as follows.

That is, as mentioned above, the descending length of the drive shaft 21 from the position where its lower end and the liquid level are at the same height is defined as X,
The stand 2 as the drive shaft 21 enters the liquid 24
8a, and furthermore, let y be the amount of descent of the container 23, W(x) be the increase in the apparent weight of the liquid 24, and let U be the length of penetration from the liquid level at the lower end of the drive shaft 21 (from the lower end of the drive shaft 21). In a state where the liquid level is the same height, x = 0 and u = 0, and in a state where the drive shaft 21 is not immersed in the liquid 24, y = o and W(x).
= O), the density of the liquid 24 is σ, the volume of the infiltration of the drive shaft 2l into the liquid 24 is V (u), the cross-sectional area inside the container 23 is SC%, the spring constant of the precision spring scale 28 is K Then, the above W(x) is W (x) = V (u)・σt
-(1), where V(u) is equal to the apparent liquid increase, so V(u) = (u x) Sc + y-Sc
-(2), and the amount of descent y of the container 23 is determined by the following equation based on the spring constant K.

V (u)・σ, y = 7-(3) Therefore, from equations (2) and (3), V(u) = (u-x) Sc0''(u''''' ScK, which is By rearranging, K'Sc V (u) = (u − x)
--- (4)K-σ1・S, and substituting this equation (4) into equation (1), W(x)
=A (u-x) --(5).

However, A = 52 J Uni''.

K-σ1・S, Next, when we differentiate equation (1) with respect to X, we get ? W (x) d V (u) 1 ■. σ, ・− (6)dx
dx, and if we differentiate equation (5) with respect to X, we get d W (X
) = A (du-1> ,,-,,
<7) dx dx.

On the other hand, the drive shaft 21 has a penetration length of U from the liquid level.
The cross-sectional area S (u) near the liquid level is equal to the volume V (u) of the infiltration of the drive shaft 21 into the liquid 24, differentiated by U, so S (・) 1ν Bowman 1H Keen・”L-(8)du
dx du , and if we set B = d W (x) /dx here, then from equations (6), (7) and (8), BA S (u) = 7·8-,A.

Therefore, since the density σ of the liquid 24, the cross-sectional area S of the inside of the container 23, and the spring constant K of the precision spring balance 28 are known in advance, for example, while continuously lowering the drive shaft 21, input By determining the amount of apparent weight decrease each time the drive shaft 21 descends a certain distance based on the signal, the amount of change dx in the descending length X of the drive shaft 21 is calculated.
By finding the ratio B of the amount of change dW(x) in the apparent weight W(x) of , U can be found by substituting W (x) and Therefore, the outer diameter of each part and the position of the part where the radial dimension changes can be determined from the cross-sectional area distribution.

By the way, if the spring constant K is chosen so that K=σ,・S, the height of the liquid level can be kept constant, so from equation (4), u=x, and equation (9) becomes, S(u)-B/σ,
Therefore, the descending length of the drive shaft 21
The relationship between S (u) and the cross-sectional area S (u) can be directly determined.

The personal computer 30 outputs the values of the outer diameter of each part of the drive shaft 2l and the position of the part where the radial dimension changes, determined in this way, on the display device 3l or a printer (not shown), and also inputs a rough estimate. Compare the calculated values with the error tolerance ranges for the outside diameter and position, and if the values are within the error tolerance range, the results will be passed, and if they are outside the error tolerance ranges, the results will be rejected. It is output by the display device 31 or a printer (not shown).

Therefore, according to the apparatus of this embodiment, the dimensions of each part of the drive shaft 21 as an axially symmetrical product can be measured simply by placing it in the liquid 24 in the container 23 whose size can be freely set. Measurement and inspection can be performed at low cost and with high precision within the possible range.

Although the above has been described based on the illustrated example, the present invention is not limited to the above-mentioned example. For example, the measurement object input/output means may be a motor-driven nut 1 or In such a case, automatic measurement is also possible by appropriately controlling the operation of the motor using the CPU 4 so as to be linked to the measurement.

Furthermore, it goes without saying that the present invention can also be used to measure the cross-sectional area of forging models for products other than the above-mentioned crankshafts and axially symmetric products other than the above-mentioned drive shafts.

(Effects of the Invention) Thus, according to the device of the present invention, the cross-sectional area distribution of the object to be measured can be automatically and non-destructively measured with high accuracy using a simple device, so this device can be applied to a forging model. For example, the volume distribution in the longitudinal direction can be determined with high precision, and the volume distribution of the forged material can be made sufficiently good.In addition, if this device is applied to axially symmetric products, the dimensions of each part can be measured over a wide range. can be measured and inspected at low cost and with high precision.

[Brief explanation of drawings]

Figure 1 shows the structure of an embodiment in which the cross-sectional area measuring device of the present invention is applied to the measurement of a forging model, and Figures 2 (a) and (b) show the cross-sectional area using the device of the above embodiment. An explanatory diagram showing the measurement method, FIG. 3 is a diagram showing the configuration of another embodiment in which the cross-sectional area measuring device of the present invention is applied to the measurement of axially symmetrical products, and FIGS. 4(a) and (b) are the above-mentioned and other Explanatory diagram showing the cross-sectional area measuring method using the apparatus of the example, FIG. 5(a) ~
(c) is an explanatory drawing showing the forging process of a crankshaft as an example of a forged product, Fig. 6 is a cross-sectional diagram showing the cross-sectional area distribution of the crankshaft determined from the drawing dimensions and shape, and Fig. 7 is axially symmetrical. FIG. 8 is an explanatory diagram showing a conventional method for measuring the radial dimension of a product. FIG. 1-crankshaft 3, 23-・1 container 4, 24・
1. Liquid 5. Lifting mechanism 11.1 Load cell
12-... Rotary encoder C p u
21--Drive shaft robot 26- Robot control device precision spring scale 29--Signal conversion control device personal computer

Claims (1)

[Claims] 1. A container (3) that stores a liquid (4) with a predetermined specific gravity, and a measuring object (1, 21), with its longitudinal direction being perpendicular to the liquid in the container. Measurement object loading/unloading means (5, 25) for loading and unloading the measurement object; penetration length measuring means (12, 25) for measuring the penetration length of the measurement object into the liquid in the container; an apparent weight measuring means (11, 28) for measuring the apparent weight of the liquid or the apparent weight of the object to be measured that has penetrated into the liquid; the specific gravity of the liquid; the measured penetration length; and A cross-sectional area measuring device comprising: cross-sectional area calculation means (14, 30) for calculating the cross-sectional area of the object to be measured near the liquid surface based on the apparent weight.