A device for accurately measuring the outer diameter of thin walls

Abstract

A device for accurately measuring the outer diameter of a thin-walled part, the main point of which is that it is composed of a base plate, a gauge block, a positioning block, a support rod, and a standard body. The standard body has the same shape and size as the corresponding position of the measured part of the measured part. The gauge block, the positioning block, and the support rod are fixed to the surface of the base plate at the same time. The gauge block is opposite to the support rod. The inner surface of the positioning block is parallel to the center line of the dial indicator contact, and the distance between the two is equal to the radius of the measured part of the measured part. The dial indicator is fixed on the support rod, and the center line of the dial indicator contact coincides with the diameter of the measured part of the measured part. The advantages of the utility model are: simple structure, convenient measurement operation, the position of the measuring body is ensured by positioning the gauge block and the positioning block, and the special flat dial indicator contact is designed, so that the outer wall of the measured part is measured by three planes tangent to the outer wall, and the contact point of the measurement is changed to the distance between the tangents, which can realize the accurate measurement of the outer diameter of the thin-walled part, and is suitable for batch production inspection.

Description

Technical Field

[0001] The utility model relates to a measuring device, in particular to a measuring device for the outer diameter of a thin wall. Background Art

[0002] This product parts are similar to ( Figure 1 ) shown in the figure, in this example, the ring part to be measured is φ79.1 -0.06 -0.18 This size, this type of parts has thin walls, is easy to deform, and has a small outer diameter tolerance. When inspecting the outer diameter of the parts, we usually use universal measuring tools such as vernier calipers or micrometers. It takes a certain amount of time to find the diameter each time. At the same time, the different strength of the surveyor each time will also affect the measurement result. In batch production, it shows its low efficiency and cannot meet its production inspection requirements. The accuracy is greatly affected by the operator's experience. Summary of the invention

[0003] The utility model aims to overcome the technical defects in measuring the outer diameter of thin-walled parts and to provide a device which can measure the outer diameter of thin-walled parts quickly and accurately without being affected by the clamping force of the measurer.

[0004] The technical scheme adopted by the utility model is a device for accurately measuring the outer diameter of a thin-walled part. The main points are that the device is composed of a base plate, a gauge block, a positioning block, a support rod and a standard body. The standard body has the same shape and size as the corresponding position of the measured body. The gauge block, the positioning block and the support rod are fixed to the surface of the base plate at the same time. The gauge block is opposite to the support rod. The inner surface of the positioning block is parallel to the center line of the dial indicator contact, and the distance between the two is equal to the radius of the measured body at the measured position. The dial indicator is fixed on the support rod, and the center line of the dial indicator contact coincides with the diameter of the measured body at the measured position.

[0005] The standard body is a cylindrical body that is consistent with the shape of the workpiece being measured, and is equal to the outer diameter of the measured workpiece at the same height. It is used to calibrate the measuring device and the dial indicator to zero. Before each inspection of the measuring body, the device is inspected with the standard body. The positioning block ensures that the position of the gauge block and the dial indicator contact is the diameter of the measured object. In this way, during batch inspection, as long as the measuring body is pushed in, the test data can be obtained in the dial indicator to determine whether the measuring body is qualified.

[0006] The gauge block is fixed to the bottom plate surface by a fixing part, opposite to the supporting rod, the center line of the gauge block coincides with the center line of the dial indicator contact, and the height of the gauge block is within the height range of the measuring surface of the workpiece to be measured.

[0007] The middle of the side of the gauge block opposite to the support rod is machined with a measuring protrusion, and the height of the measuring protrusion is within the height range of the measuring surface of the workpiece being measured. The gauge block is machined with the measuring surface only in the middle, which can ensure high machining accuracy and low cost.

[0008] The fixing part has two bolts symmetrically arranged with respect to the center line, and a positioning pin is arranged on the outer side of each bolt. The bolts and the positioning pin are provided with matching fixing holes on the gauge block and the bottom plate. The bolts and the positioning pin are used together to ensure the installation accuracy of the gauge block and ensure that the measuring protruding surface of the gauge block is tangent to the diameter of the measuring body.

[0009] The dial gauge contact measuring surface is a plane. When the dial gauge contact measuring surface is a plane, the installation accuracy of the dial gauge contact can be reduced, because the measurement position is not limited to the tangent point between the dial gauge contact and the measured object, but the tangent line. The center line of the dial gauge contact and the diameter of the measured object are on the same plane and parallel, and are on the tangent line between the dial gauge contact measuring surface and the measured object.

[0010] The front end of the measuring surface of the meter contact has a slope that is larger outside and smaller inside. The slope is a guide surface that can ensure that the object to be measured enters the measuring area smoothly.

[0011] The outer diameter of the standard body is the minimum or maximum value of the diameter of the measured body. The pointer of the dial indicator can swing to both sides with the zero point. Using the critical value as the standard body, when measuring, just pay attention to whether the value of the swing to one side is in the qualified area, and swinging to the other side must be unqualified.

[0012] The utility model has the advantages of simple structure and convenient measurement operation. The position of the measuring body is ensured by positioning the gauge block and the positioning block, and a specially designed plane dial indicator contact is used, so that the outer wall of the measured body is measured by three planes tangent to the outer wall, and the distance between the tangents is changed from the measured contact point, so that the outer diameter of the thin-walled part can be accurately measured. The device is easy to implement and can meet the use requirements to make the measurement result accurate, and is suitable for mass production inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the structure of the object being measured

[0014] Figure 2 Schematic diagram of the standard structure

[0015] Figure 3 A top view of the detection standard body of the utility model

[0016] Figure 4 The utility model is used in the state diagram when detecting the workpiece to be measured

[0017] Figure 5 Schematic diagram of the structure of the special table contact

[0018] Figure 6 for Figure 5 Side view

[0019] Figure 7 for Figure 5 Top view

[0020] Wherein: 1 gauge block 101 measuring protruding surface 2 bolt 3 bottom plate 4 positioning pin 5 positioning block 6 standard body 7 support rod 8 small round nut 9 screw 10 dial indicator 11 meter contact 12 inclined surface 13 measured workpiece 131 measured part. DETAILED DESCRIPTION

[0021] The utility model is further described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can better understand the utility model. Modifications, additions and substitutions to the following embodiments are possible without exceeding the protection scope of the utility model.

[0022] like Figure 2-6 As shown, a device for accurately measuring the outer diameter of thin-walled parts is composed of a base plate 3, a gauge block 1, a positioning block 5, a support rod 7, and a standard body 6. The standard body has the same shape and size as the corresponding position of the measured body. The utility model uses the same appearance as the measured workpiece 13, and the inner diameter is smaller than the measured workpiece, which is changed from φ76 to φ60 (or smaller), so that the overall wall thickness is increased from 1.5mm to 9.5mm. If the weight is not considered, a solid body or a cylinder with a sufficiently thick wall can even be used. The height of the precision machined surface is the same as that of the measured body. It is used to calibrate the measuring device and the dial indicator to zero. In order to increase its wear resistance, tool steel is generally used and heat-treated. In this example, the standard body has the same diameter as the measured body. Since there is a tolerance in the design size of the measured body in the design (φ79.1 -0.06 -0.18 ), the outer diameter range of the standard body is φ79.04-φ78.92mm, which is qualified. The outer diameter of the standard body is the minimum or maximum value of the diameter of the measured body to facilitate subsequent measurements. The critical value is used as the standard body. When measuring, just pay attention to whether the value of its swing to one side is in the qualified area, and swinging to the other side must be unqualified. Before each inspection of the measuring body, first inspect the device with a standard body. Press the dial indicator's contact to the standard body for 1 or 2mm and then return to zero, so that the dial indicator has a certain amount of compression to prevent the contact from not contacting the measured body during measurement and affecting the measurement accuracy. The compression of a general dial indicator is 5mm, which can be reflected on the small pointer on the dial.

[0023] The gauge block 1, the positioning block 5, and the support rod 7 are fixed on the bottom plate at the same time. The gauge block and the positioning block are accessories dedicated to the workpiece to be measured, which determine the center of the workpiece to be measured and the height of the measured part. The gauge block is opposite to the support rod. The inner surface of the positioning block is parallel to the center line of the dial gauge contact 11, and the distance between the two is equal to the radius of the measured part of the measured body. A vertical line is drawn from the center of the measured workpiece to the positioning block, and the vertical center should be on the inner surface of the positioning block. The dial gauge is fixed on the support rod 7, and the center line of the dial gauge contact coincides with the diameter of the measured part of the measured body. The support rod is a universal part as a fixing part of the dial gauge. Usually, the horizontal position of its center line remains unchanged, but the height is adjustable. As shown in the figure, the center hole of the support rod is used to install the dial gauge 10, and the screw 9 at the top plays the role of fixing the dial gauge. The support rod is designed with threads at the bottom, which cooperates with the threaded holes on the bottom plate 3 to adjust the height of the measuring position. The small round nut 8 is used to fix the support rod to ensure the function of the dial gauge measuring position.

[0024] The gauge block 1 is fixed to the bottom plate surface by a fixing part, opposite to the supporting rod, the center line of the gauge block coincides with the center line of the dial indicator contact, and the height of the gauge block is within the height range of the measuring surface of the workpiece to be measured.

[0025] Since the measuring surface of the gauge block is a precision-machined surface, a measuring protrusion 101 is machined in the middle of the surface of the gauge block 1 opposite to the support rod 7 for detection. The height of the measuring protrusion is within the height range of the measuring surface of the workpiece being measured.

[0026] The original purpose of the gauge block is to determine the diameter line of the workpiece together with the dial indicator. However, in the embodiment of the present application, the measuring surface of the workpiece to be measured is at a specific height, and there is a cylindrical surface above the measuring surface that is larger than the measuring surface. Therefore, the gauge block cannot be higher than the measuring surface in height. Figure 1 It can be seen that the height of the measuring surface is between 20.5 and 12 mm (the actual measuring position is 8.5 mm), and the height of the meter contact and the measuring protruding surface should also be within this range.

[0027] The fixing parts of the gauge block have two bolts 2 symmetrically arranged with the center line, and there is a positioning pin 4 on the outside of each bolt to prevent the deflection of the gauge block 1. The gauge block and the bottom plate have matching fixing holes corresponding to the bolts and the positioning pins. The bolts and the positioning pins are used together to ensure the installation accuracy of the gauge block and ensure that the measuring protruding surface of the gauge block is tangent to the diameter of the measuring body.

[0028] The bottom plate 3 is rectangular, and the gauge block 1 and the positioning block 5 are fixed to the two right-angled sides of the bottom plate respectively. The positioning block is between the gauge block and the dial contact. The inner surface of the positioning block is parallel to the center line of the dial indicator's dial contact 11, and the distance between the two is equal to the radius of the measured part of the measured object. The height of the positioning block must also be within the height range of the measuring surface of the workpiece being measured. The measuring surface of the dial indicator's dial contact is a plane. The dial indicator's dial contact uses a specially designed flat-head dial contact to replace the universal dial indicator contact, so that the measurement is changed from the tangent point to the tangent surface. The thread on the dial contact matches the thread of the standard dial indicator. After the thread of the A and B surfaces of the dial contact are screwed in place, they must be parallel to the surface of the dial indicator to make the measurement more accurate. The distance between the A and B surfaces of the dial contact is 8mm.

[0029] The measuring protruding surface of the gauge block, the inner surface of the positioning block, and the measuring surface of the meter contact are all tangent to the measuring circumference of the workpiece to be measured, so as to ensure that the workpiece to be measured can be accurately centered when pushed into the space formed by the gauge block, the positioning block, and the meter contact. The front end of the meter contact measuring surface of the dial indicator has a slope 12 that is larger on the outside and smaller on the inside, which is convenient for guiding the entry of the workpiece to be measured. The remaining parts not described are the same as the prior art.

[0030] The method of using the utility model is as follows: before testing the workpiece to be measured, first calibrate the measuring device with a standard body 6 with a size of φ78.92mm, push the standard body 6 along the bottom plate 3, make the measured outer cylindrical surface of the standard body 6 contact the end faces of the gauge block 1 and the positioning block 5 respectively, adjust the dial indicator contact to ensure that the end face of the dial indicator contact is parallel to the end face of the gauge block 1, and make the pointer have an appropriate amount of pressure (1 or 2mm), and return the dial indicator value to zero. Remove the standard body, push the measuring piece along the bottom plate 3, repeat the above operation, if the value of the pointer jump is within the tolerance range of the outer diameter size (0-0.12mm), the product part size is qualified.

Claims

1. A device for accurately measuring the outer diameter of a thin wall, characterized by: It consists of a base plate, a gauge block, a positioning block, a supporting rod and a standard body. The standard body has the same shape and size as the corresponding position of the measured part of the measured object. The gauge block, the positioning block and the supporting rod are fixed on the surface of the base plate at the same time. The gauge block is opposite to the supporting rod. The inner surface of the positioning block is parallel to the center line of the dial indicator's contact, and the distance between the two is equal to the radius of the measured part of the measured object. The dial indicator is fixed on the supporting rod, and the center line of the dial indicator's contact coincides with the diameter of the measured part of the measured object.

2. The device for accurately measuring the outer diameter of a thin wall according to claim 1, characterized in that: The gauge block is fixed to the surface of the base plate via a fixing part, opposite to the supporting rod, the center line of the gauge block coincides with the center line of the dial indicator contact, and the height of the gauge block is within the height range of the measuring surface of the workpiece being measured.

3. The device for accurately measuring the outer diameter of a thin wall according to claim 2, characterized in that: A measuring protrusion is processed in the middle of one side of the gauge block opposite to the support rod, and the height of the measuring protrusion is within the height range of the measuring surface of the workpiece to be measured.

4. The device for accurately measuring the outer diameter of a thin wall according to claim 2, characterized in that: The fixing part has two bolts symmetrical with respect to the center line, and a positioning pin is respectively arranged on the outer side of the bolts. The gauge block and the bottom plate are provided with fixing holes corresponding to the bolts and the positioning pins and matching with them.

5. The device for accurately measuring the outer diameter of a thin wall according to claim 1, characterized in that: The measuring surface of the dial indicator's contact is flat.

6. The device for accurately measuring the outer diameter of a thin wall according to claim 5, characterized in that: The front end of the measuring surface of the meter contact is provided with an inclined surface which is larger outside and smaller inside.

7. The device for accurately measuring the outer diameter of a thin wall according to claim 1, characterized in that: The outer diameter of the standard body is the minimum or maximum diameter of the measured part of the measured body.

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