Position degree measuring method

Abstract

The invention discloses a location degree measuring method in the technical field of location degree measurement, which comprises the following steps of: manufacturing a sample piece, enabling the distance between the center of an inner curve of the sample piece and the center of a connecting line of two pin holes to be 0 in the X direction, placing the sample piece in the middle position of a measuring system, and measuring the location degree of the two pin holes. At the moment, the side clearance between the left positioning pin and the left pin hole of the sample piece is p, the side clearance between the right positioning pin and the right pin hole of the sample piece is also p, the reading of the left side head L is L0, the reading of the right measuring head R is R0, the sample piece is pushed rightwards, so that the left pin hole is tangent to the left positioning pin, the left measuring head L is increased, and the right measuring head R is decreased. According to the method, the two positioning pins and the two displacement measuring heads are installed on the flat table top, the method described in the steps is adopted, the position degree of the inner curve with the two pin holes as the benchmark in the measured part can be rapidly measured, and compared with three-coordinate measurement, the measuring method has the advantages of being professional and high in measuring efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of position measurement, and in particular to a position measurement method. Background Art

[0002] With the development of modern mechanical processing and manufacturing industry, the structure of mechanical parts is becoming more and more complex, and the quality requirements on parts are also correspondingly improved. Sometimes some holes are processed on the parts to meet some functional requirements. The accuracy of measuring the position of the inner curve of the part based on the double pin hole directly affects the quality of the part. Therefore, in the process of part manufacturing, measuring the position of the inner curve is also a very important process.

[0003] At present, the three-coordinate measuring machine is mainly used to scan and collect data points on the surface of the measured part to obtain the three coordinates of the measured part in the space, so as to obtain the position of the curve inside the part. However, the three-coordinate measuring machine is expensive and cannot be used for batch measurement. The measurement efficiency is low, and the measurement process is complicated and troublesome, and time-consuming. The long time makes the production cost of the enterprise high. Summary of the invention

[0004] The invention solves the problems that the existing three-coordinate measuring instrument has high cost and cannot perform batch measurement, has low measurement efficiency, and has a complex and troublesome measurement process, and is time-consuming and long, which makes the production cost of the enterprise high, and provides a position measurement method.

[0005] The present invention adopts the following technical scheme: a position measurement method, comprising the following steps:

[0006] Step 1: Make a sample, and in the X direction, make the distance between the center of the inner curve of the sample and the center of the line connecting the two pin holes 0;

[0007] Step 2: Place the sample in the middle of the measuring system. At this time, the side clearance between the left locating pin and the left pin hole of the sample is p, and the side clearance between the right locating pin and the right pin hole of the sample is also p. The reading of the left head L is L0, and the reading of the right probe R is R0.

[0008] Step 3: Push the sample to the right so that the left pin hole is tangent to the left positioning pin. Compared with step 2, the left probe L eats more and the right probe R eats less. At this time, the readings of the left probe L and the right probe R are LY1 and RY1 respectively. Obviously:

[0009] LY1=L0+p (1),

[0010] RY1=R0-p (2);

[0011] Step 4: Push the sample to the left so that the right pin hole is tangent to the right positioning pin. Compared with step 2, the left probe L eats less and the right probe R eats more. At this time, the readings of the left probe L and the right probe R are LY2 and RY2 respectively. Obviously:

[0012] LY2=L0-p (3),

[0013] RY2=R0+p (4);

[0014] Step 5: Take a product whose pin hole diameter is Δ larger than the sample diameter, and the center of the inner curve is offset to the right by e relative to the center of the line connecting the two pin holes. Place the product in the middle of the measurement system. At this time, the readings of the left probe L and the right probe R are recorded as LX0 and RX0 respectively. Compared with step 2, it is obvious that:

[0015] LX0=L0+e (5),

[0016] RX0=R0-e (6);

[0017] Step 6: Push the product to the right so that the left pin hole is tangent to the left positioning pin. Compared with step 5, the left probe L eats more and the right probe R eats less. At this time, the readings of the left probe L and the right probe R are LX1 and RX1 respectively. Obviously:

[0018] LX1=LX0+p+Δ=L0+e+p+Δ (7),

[0019] RX1=RX0-(p+Δ)=R0-ep-Δ (8);

[0020] Step 7: Push the product to the left so that the right pin hole is tangent to the right positioning pin. Compared with step 5, the left probe L eats less and the right probe R eats more. At this time, the readings of the left probe L and the right probe R are LX2 and RX2 respectively. Obviously:

[0021]

[0022] Step 8: Based on the above expression, add (7)+(9)-(8)-(10) and arrange them to get:

[0023] LX1+LX2-RX1-RX2=2L0-2R0+4e (11);

[0024] From the above formula, we can get:

[0025]

[0026] In the above formula, LX1, LX2, RX1, RX2 are the readings of the probe, which are known. (2L0-2R0) is the inherent parameter of the measurement system. Let C = 2L0-2R0. C can be obtained by steps 2 and 3. (1) + (3) - (2) - (4) are combined and the following is obtained: LY1 + ​​LY2 - RY1 - RY2 = 2L0 - 2R0.

[0027] That is, C = 2L0-2R0 = LY1+LY2-RY1-RY2 (13);

[0028] In the above formula, LY1, LY2, RY1, RY2 are the readings of the probe when measuring the sample, which are known, so we can get

[0029] Optionally, the direction of the line connecting the two pin holes is the X direction, and the compression of the probe is called "eating the gauge", and the increase in the compression of the probe is called "increasing the eating of the gauge".

[0030] By adopting the above technical solution, the method can be easily described.

[0031] Optionally, the diameters of the left locating pin and the right locating pin are a certain size smaller than the diameter of the pin hole.

[0032] By adopting the above technical solution, it is ensured that both pin holes of the measured part can be inserted by the left locating pin and the right locating pin at the same time.

[0033] In summary, the present invention includes at least one of the following beneficial effects:

[0034] This measurement method is based on the symmetrical shape characteristics based on the double pin holes. For the measured part, by installing two positioning pins and two displacement probes on a flat table and using the above measurement method, the position of the center of the curve in the measured part deviating from the center of the line connecting the two pin holes along the direction of the pin hole line can be quickly measured. Compared with three-coordinate measurement, this measurement method is professional, has high measurement efficiency, and has a simple measurement mechanism structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The structure of the tested part of the present invention is schematically shown in FIG. Figure 1 ;

[0036] Figure 2 The structure of the tested part of the present invention is shown in FIG. Figure 2 ;

[0037] Figure 3 It is a schematic diagram of the principle of step 2 of the position measurement method of the present invention;

[0038] Figure 4 It is a schematic diagram of the principle of step 3 of the position measurement method of the present invention;

[0039] Figure 5 It is a schematic diagram of the principle of step 4 of the position measurement method of the present invention;

[0040] Figure 6 It is a schematic diagram of the principle of step 5 of the position measurement method of the present invention;

[0041] Figure 7 It is a schematic diagram of the principle of step 6 of the position measurement method of the present invention;

[0042] Figure 8 This is a schematic diagram of the principle of step seven of the position measurement method of the present invention. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1-8 The present invention is described in further detail.

[0044] An embodiment of the present invention provides a method for measuring position, wherein the relevant part of the part drawing is as follows: Figure 1 As shown, this position measurement method is used to measure Figure 1 The deviation of the center of the inner curve of the middle part from the center of the two pin control lines along the direction of the pin hole line is j|0.04|AB.

[0045] like Figure 2 As shown in the figure, the required measurement system consists of: a left locating pin, a right locating pin, a left probe L, and a right probe R are fixedly installed on a flat work surface. Since the distance between the two pin holes of the parts has a tolerance, in order to allow the two pin holes of all parts to be inserted by the left locating pin and the right locating pin, the diameter of the left locating pin and the right locating pin must be a certain size smaller than the diameter of the pin hole. For the convenience of description, the direction of the line connecting the two pin holes is recorded as the X direction, the compression of the probe is called "eating the table", and the increase in the compression of the probe is called "increasing the table".

[0046] The specific steps include:

[0047] Step 1: Make a sample, and in the X direction, make the distance between the center of the inner curve of the sample and the center of the line connecting the two pin holes 0 (since it is impossible to be completely 0, in fact, it can be much smaller than the position tolerance of the product).

[0048] Step 2: Imagine placing the sample in the middle of the measurement system. Figure 3 As shown in the figure, at this time, the side clearance between the left locating pin and the left pin hole of the sample is p, and the side clearance between the right locating pin and the right pin hole of the sample is also p. The reading of the left head L is L0, and the reading of the right probe R is R0. Since the left head L and the right probe R cannot be installed completely symmetrically relative to the left locating pin and the right locating pin, generally speaking, L0 and R0 are not equal. And because this state is hypothetical and cannot be actually operated, we cannot directly know the values ​​of L0 and R0.

[0049] Step 3: Push the sample to the right so that the left pin hole is tangent to the left positioning pin. Figure 4 As shown in the figure, compared with step 2, the left probe L consumes more and the right probe R consumes less. At this time, the readings of the left probe L and the right probe R are recorded as LY1 and RY1 respectively. Obviously:

[0050] LY1=L0+p (1),

[0051] RY1=R0-p (2).

[0052] Step 4: Push the sample to the left so that the right pin hole is tangent to the right positioning pin. Figure 5 As shown in the figure, compared with step 2, the left probe L consumes less meter, and the right probe R consumes more meter. At this time, the readings of the left probe L and the right probe R are recorded as LY2 and RY2 respectively. Obviously:

[0053] LY2=L0-p (3),

[0054] RY2=R0+p (4).

[0055] Step 5: Take a product whose pin hole diameter is Δ larger than the sample diameter, and the center of the inner curve is offset to the right by e relative to the center of the line connecting the two pin holes. Assume that the product is placed in the middle of the measurement system, such as Figure 6 As shown, the readings of the left probe L and the right probe R are recorded as LX0 and RX0 respectively. Compared with step 2, it is obvious that:

[0056] LX0=L0+e (5),

[0057] RX0=R0-e (6).

[0058] Step 6: Push the product to the right so that the left pin hole is tangent to the left positioning pin. Figure 7 As shown in the figure, compared with step 5, the left probe L consumes more meter, and the right probe R consumes less meter. At this time, the readings of the left probe L and the right probe R are recorded as LX1 and RX1 respectively. Obviously:

[0059] LX1=LX0+p+Δ=L0+e+p+Δ (7),

[0060] RX1=RX0-(p+Δ)=R0-ep-Δ (8).

[0061] Step 7: Push the product to the left so that the right pin hole is tangent to the right positioning pin. Figure 8 As shown in the figure, compared with step 5, the left probe L consumes less, and the right probe R consumes more. At this time, the readings of the left probe L and the right probe R are recorded as LX2 and RX2 respectively. Obviously:

[0062] LX2=LX0-(p+Δ)=L0+ep-Δ (9),

[0063] RX2=RX0+p+Δ=R0-e+p+Δ (10).

[0064] Step 8: Based on the above expression, add (7)+(9)-(8)-(10) and arrange them to get:

[0065] LX1+LX2-RX1-RX2=2L0-2R0+4e (11),

[0066] From the above formula, we can get:

[0067]

[0068] In the above formula, LX1, LX2, RX1, RX2 are the readings of the probe, which are known, (2L0-2R0) is the inherent parameter of the measurement system, and C=2L0-2R0. C can be obtained through steps 2 and 3.

[0069] Arrange (1)+(3)-(2)-(4) and we get: LY1+LY2-RY1-RY2=2L0-2R0,

[0070] That is, C = 2L0-2R0 = LY1+LY2-RY1-RY2 (13),

[0071] In the above formula, LY1, LY2, RY1, RY2 are the readings of the probe when measuring the sample, which are known, so we can get

[0072] Conclusion: For the position of a symmetrical feature based on two pin holes, the position of the feature can be measured by installing two locating pins and two displacement probes on a flat table using the method described in the above steps. The offset e of the feature is calculated by the above formula (14), where C is the inherent constant of the system and can be obtained by measuring the sample.

[0073] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A position measurement method, characterized in that: The following steps are involved: Step 1: Make a sample, and in the X direction, make the distance between the center of the inner curve of the sample and the center of the line connecting the two pin holes 0; Step 2: Place the sample in the middle of the measuring system. At this time, the side clearance between the left locating pin and the left pin hole of the sample is p, and the side clearance between the right locating pin and the right pin hole of the sample is also p. The reading of the left head L is L0, and the reading of the right probe R is R0. Step 3: Push the sample to the right so that the left pin hole is tangent to the left positioning pin. Compared with step 2, the left probe L eats more and the right probe R eats less. At this time, the readings of the left probe L and the right probe R are LY1 and RY1 respectively. Obviously: LY1=L0+p (1), RY1=R0-p (2); Step 4: Push the sample to the left so that the right pin hole is tangent to the right positioning pin. Compared with step 2, the left probe L eats less and the right probe R eats more. At this time, the readings of the left probe L and the right probe R are LY2 and RY2 respectively. Obviously: LY2=L0-p (3) RY2=R0+p (4); Step 5: Take a product whose pin hole diameter is Δ larger than the sample diameter, and the center of the inner curve is offset to the right by e relative to the center of the line connecting the two pin holes. Place the product in the middle of the measurement system. At this time, the readings of the left probe L and the right probe R are recorded as LX0 and RX0 respectively. Compared with step 2, it is obvious that: LX0=L0+e (5), RX0=R0-e (6); Step 6: Push the product to the right so that the left pin hole is tangent to the left positioning pin. Compared with step 5, the left probe L eats more and the right probe R eats less. At this time, the readings of the left probe L and the right probe R are LX1 and RX1 respectively. Obviously: LX1=LX0+p+Δ=L0+e+p+Δ (7), RX1=RX0-(p+Δ)=R0-ep-Δ (8); Step 7: Push the product to the left so that the right pin hole is tangent to the right positioning pin. Compared with step 5, the left probe L eats less and the right probe R eats more. At this time, the readings of the left probe L and the right probe R are LX2 and RX2 respectively. Obviously: LX2=LX0-(p+Δ)=L0+ep-Δ (9), RX2=RX0+p+Δ=R0-e+p+Δ (10); Step 8: Based on the above expression, add (7)+(9)-(8)-(10) and arrange them to get: LX1+LX2-RX1-RX2=2L0-2R0+4e (11); From the above formula, we can get: In the above formula, LX1, LX2, RX1, RX2 are the readings of the probe, which are known. (2L0-2R0) is the inherent parameter of the measurement system. Let C = 2L0-2R0. C can be obtained by steps 2 and 3. (1) + (3) - (2) - (4) are combined and the following is obtained: LY1 + ​​LY2 - RY1 - RY2 = 2L0 - 2R0. That is, C = 2L0-2R0 = LY1+LY2-RY1-RY2 (13); In the above formula, LY1, LY2, RY1, RY2 are the readings of the probe when measuring the sample, which are known, so we can get 2. A position measurement method according to claim 1, characterized in that: The direction of the line connecting the two pin holes is the X direction. The compression of the probe is called "eating the gauge", and the increase in the compression of the probe is called "increasing the eating of the gauge".

3. A position measurement method according to claim 1, characterized in that: The diameters of the left and right locating pins are a certain size smaller than the diameter of the pin hole.

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