JPH0650746A - Size measuring device - Google Patents

Abstract

PURPOSE:To make possible the estimation of size of a work in the case where it goes to outside air temperature by basing on detected temperature thereof, the outside air temperature, work size and a linear expansion coefficient thereof. CONSTITUTION:A processor 5 serves to take in, for instance, a distance size L1 from the terminal of the output of a third sensor 3 up to an edge of a case thereof and in addition, also another distance size L2 from the terminal of the output of a fourth sensor 4 up to another edge of the case. On the other hand, the output of a first sensor 1 indicating the outside air temperature T1 of the circumference of the case and the other output of a second sensor 2 indicating temperature T2 of the case itself are taken in. A measured value of the size L at the temperature T2 is calculated on the basis of the sizes L1, L2 detected with the size detection sensors 3, 4 and the operation of the size L (estimation) is performed on the basis of the following expression. L (estimation)=L(measured value) x{1+(T1+T2) x K, K indicates a linear expansion coefficient of the case. The obtained size L(estimation) is shown on a display 8 and printed out with a bar code printer 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the size of a work, and more particularly to a size measuring device capable of estimating the size of the work when the temperature of the work reaches the ambient temperature.

[0002]

2. Description of the Related Art A shim (thickness adjusting plate) used for assembling an automobile or the like must have an appropriate thickness in view of its purpose of use. Therefore, conventionally, in order to select a shim having a thickness suitable for a work, the size of the work is actually measured.

By the way, for example, when a work is washed, the work is dried with hot air, but within a certain period after the drying process, the work is heated to a temperature considerably higher than the outside air temperature. Present.

The dimension measurement result of the work in such a state is considerably different from the dimension measurement result under the same work temperature as the outside air temperature. This is because the work has expanded after the drying process.

Therefore, it is conceivable to measure the above dimensions after the temperature of the work is lowered to the outside air temperature.
Due to the production tact, process sequence, etc., it is actually difficult to wait until the temperature of the work becomes stable.Therefore, at present, the operator's intuition is added to the dimension measurement results when the temperature of the work is not stable. Then select the sim.

[0006]

When selecting a shim that takes into consideration the operator's intuition, it is often the case that an error in the selection is found after the work has been assembled. In that case, the shim must be removed by removing the assembled work. Since the operation of replacing the work and assembling the work is performed again, the productivity is significantly impaired.

In view of such a situation, an object of the present invention is to provide a work size measuring apparatus capable of estimating the size of the work when the temperature of the work reaches the outside air temperature.

[0008]

According to the present invention, there is provided a first temperature detecting means for detecting a temperature of a work, a second temperature detecting means for detecting an outside air temperature, and a size detecting means for detecting a size of the work. And the temperature detected by the first and second temperature detecting means, the dimension detected by the dimension detecting means, and the linear expansion coefficient of the workpiece, when the temperature of the workpiece becomes the outside air temperature. And a calculation means for estimating and calculating the dimension of the work.

[0009]

The dimensions of the workpiece at the outside air temperature are the temperature of the workpiece detected by the first temperature detecting means, the outside air temperature detected by the second temperature detecting means, and the workpiece dimension detected by the dimension detecting means. , And the coefficient of linear expansion of the work is estimated and calculated.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment of the present invention shown in FIG. 1, a temperature sensor 1 for detecting an outside air temperature around a work, a temperature sensor 2 for detecting the temperature of the work, and a size detection sensor 3 for detecting the size of the work, which will be described later. , 4 and a microprocessor 5 for processing the detection signals of the sensors 1 to 4.

In this embodiment, thermocouple type sensors are used as the temperature sensors 1 and 2, and magnescales are used as the dimension detecting sensors 3 and 4.

The workpiece whose dimensions are measured by this embodiment is, for example, a transaxle case 20 for a four-wheel drive vehicle as shown in FIG. The transaxle case 20 has a configuration in which a left side portion 21 and a right side portion 22 are connected to each other, and a differential device 30 is stored inside one end portion thereof. Then, from the left side portion and the right side portion of the transaxle case 20, the front axles 31 and 32 connected to the side gears of the differential device 30 are led out, respectively.

From the rear side of the transaxle case 20, the drive bevel pinion 40 shown in FIG.
The shaft portion 41 of is derived. The drive bevel pinion 40 meshes with a drive bevel gear 50 that rotates integrally with a ring gear (not shown) of the differential device 30 shown in FIG. It is transmitted to the rear wheels through the device.

The power of the engine (not shown) is transmitted to the ring gear of the differential device 30 via the transmission 60 shown in FIG.

The shaft portion 41 of the pinion 40 includes a retainer 70 and a bearing 7 fitted to the retainer 70.
It is rotatably supported by the rear side of the case 20 via the first and the second 72, and at that time, a shim (thickness adjusting plate) 80 is provided between the inner surface of the flange portion 70a of the retainer 70 and the rear side outer surface 20a of the case 20. Is intervened. The shim 80 is used to adjust the position of the drive bevel pinion 40 in the axial direction, and if the thickness is appropriate, the pinion 40 and the drive bevel gear 50 will be meshed well. .

By the way, the differential device 30 shown in FIG. 2 is supported by the mounting hole 23 (bearing mounting hole from which the axle 32 is led out) shown in FIG. Therefore, the differential device 3
The relative positional relationship between the drive bevel gear 50 attached to No. 0 and the drive bevel pinion 40 depends on the distance dimension L from the rear outer surface 20a of the case 20 to the center of the mounting hole 23.

Therefore, in order to determine the proper thickness of the shim 80, the dimension L may be measured, but the dimension L changes depending on the temperature of the case 20. This is because the case 20 expands as the temperature of the case 20 increases.

That is, for example, Case 2 at a temperature of 20 ° C.
The reference value of the dimension L of 0 is 119.5 mm, and the case 2
0 material is a linear expansion coefficient 2.35 x (10 minus 5
If the temperature of the case 20 rises to 35 ° C., the dimension L is 119.5 mm × (35 ° C.-20 ° C.) × 2.35 × (10 Minus 5) / ° C. = 0.042 mm 2 increases.

A large number of shims 80 having different thicknesses are prepared in advance, and the change pitch of the thicknesses is 0.
It is not more than 03 mm. Therefore, when the shim thickness is determined based on the dimension L of the case 20 at the temperature of 35 ° C., the shim 80 having an appropriate thickness cannot be selected.

The case 20 is subjected to cleaning treatment and hot air drying treatment in a cleaning process before the differential device 30 and the drive bevel pinion 40 are incorporated.
After that, it is carried into a dimension measuring process for determining the shim thickness. Therefore, the case 20 carried into the dimension measuring process
The temperature is, for example, 28 ° C. to 35 ° C., which is considerably higher than the ambient outside air temperature (eg, 20 ° C. to 23 ° C.). Therefore, it is conceivable to measure the dimension L when the temperature of the case 20 has decreased to the outside air temperature, but it takes at least 90 minutes for the temperature of the case 20 to decrease to the outside air temperature.

The embodiment shown in FIG. 1 has a function of calculating the dimension L when the case 20 reaches the outside air temperature without requiring the waiting time as described above. The operation of this embodiment will be described below with reference to the flowchart of FIG. 4 which illustrates the processing procedure of the processor 5.

The case 20 carried into the dimension measuring step after the cleaning step is clamped by a clamper (not shown). Then, when the case 20 is clamped, a measurement auxiliary tool (not shown) causes the dimension detection sensor 3
Is moved forward to a preset measurement position, and when the forward movement is completed, the limit switch 6 outputs a shift completion signal. The limit switch 6 outputs a shift completion signal when the forward movement is completed.

In step 100 of FIG. 4, it is determined whether or not the shift completion signal is input. If the input is determined, the output of the sensor 3 is taken in (step 101). The output of the sensor 3 indicates the distance dimension L1 between the rear side outer surface 20a of the case 20 and one edge of the hole 23 shown in FIG.

In the next step 102, a signal indicating that the output of the sensor 3 has been captured is output to the drive system of the measurement assisting tool (step 102), whereby the measurement assisting tool pre-determines the other dimension detection sensor 4. Move forward to the set measurement position. Then, when the forward movement is completed, the limit switch 7 outputs a shift completion signal.

In step 103, it is determined whether or not the shift completion signal is input. If the input is determined, the output of the temperature sensor 1 indicating the outside air temperature T1 around the case 20, and Temperature T2 of the case 20 itself
The output of the temperature sensor 2 and the output of the sensor 4 are taken in (steps 104 and 105). The output of the sensor 4 represents the distance dimension L2 between the rear side outer surface 20a of the case 20 and the other end edge of the hole 23 shown in FIG.

When the acquisition of the signal in step 104 is completed, an acquisition completion signal is output to the drive system of the measurement assisting tool (step 106), whereby the measurement assisting tool is returned to the origin position together with the sensors 3 and 4. And
In the next step 107, the dimension L when the temperature of the case 20 becomes the outside air temperature is calculated as L (estimation).

That is, in step 107, first, an actually measured value L (actual measurement) of the dimension L at the temperature T2 is calculated based on the dimensions L1 and L2 detected by the dimension detection sensors 3 and 4, and then the following equation is obtained. Based on the above dimension L
(Estimation) is calculated. L (estimation) = L (actual measurement) × {1+ (T1-T2)} × K where K is the coefficient of linear expansion of the case 20. The coefficient of linear expansion K is known based on the material of the case 20. If it is unknown, it can be obtained as follows. That is, as shown in FIG.
Since the (actual measurement) is proportional to the temperature T2 of the case 20, the proportional constant (gradient of the graph) can be obtained as the linear expansion coefficient K.

The above dimension L (estimated) obtained by the above calculation is displayed on the display 8 shown in FIG. 1 and is printed out by the bar code printer 9.

As is apparent from the above description, according to the above embodiment, the dimension L (estimated) of the case 20 having the outside air temperature can be obtained in the state where the temperature of the case 20 is different from the outside air temperature. Therefore, an appropriate thickness of the shim 80 can be determined without waiting for the temperature of the case 20 to reach the outside air temperature.

By the way, in order to determine the proper thickness of the shim 80, the size of the pinion 40 shown in FIG. 3 is necessary in addition to the size L (estimation).
The dimension of 0 is measured with an accuracy of 0.01 mm when the temperature of the pinion 40 indicates the outside air temperature. Since the pinion 40 is not subjected to the cleaning process, its temperature is always equal to the outside air temperature.

In the above embodiment, the two size detection sensors 3,
Although the above dimension L (actual measurement) is obtained based on the output of 4,
When the measurement point is not the center of the hole, the dimension can be measured by only one dimension detection sensor, of course. Further, as the dimension detection sensor, not only the magnescale but also another appropriate stroke sensor can be used.

[0032]

According to the present invention, even when the temperature of the work is different from the outside air temperature, it is possible to estimate the size of the work when the work reaches the outside air temperature. Therefore, if it is applied to the dimension measurement of the transaxle case as shown in the embodiment, it is not necessary to wait for the temperature of the case to reach the outside air temperature, and as a result, the workability and efficiency of assembly are significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating the shape of a transaxle case.

FIG. 3 is a cross-sectional view showing how the drive bevel pinion is mounted on the transaxle case.

4 is a flowchart showing an example of a procedure executed by the processor shown in FIG.

FIG. 5 is a graph showing the relationship between measured values of dimensions and case temperatures.

[Explanation of symbols]

 1, 2 Temperature sensor 3, 4 Dimension detection sensor 5 Processor 6, 7 Limit switch 20 Transaxle case 40 Drive bevel pinion 50 Drive bevel gear 80 Shim

Claims (1)

[Claims] 1. A first temperature detecting means for detecting the temperature of the work, a second temperature detecting means for detecting the outside air temperature, a size detecting means for detecting the size of the work, and the first and the second. The size of the work when the temperature of the work reaches the outside air temperature is estimated and calculated based on the temperature detected by the temperature detection means, the size detected by the size detection means, and the linear expansion coefficient of the work. A dimension measuring apparatus comprising: a computing unit.