Precise measuring device for inner diameter of deep ring

Abstract

The utility model discloses a deep ring inner diameter precision measuring device which comprises a fixed rod, a movable rod and a check gauge, the fixed rod and the movable rod are connected through a rotating shaft to form an equal armed lever mechanism, the left end of the fixed rod is provided with a measuring head, and the right end of the fixed rod is provided with a dial indicator through a meter fixing handle; the left end of the movable rod is provided with a measuring head, the right end of the movable rod is in contact with the head of the dial indicator, a tension spring is arranged between the fixed rod and the movable rod, and the check gauge is a special standard comparison ring for checking the zero position. According to the utility model, precise measurement of the inner diameter of the deep inner ring can be effectively implemented, and the problem that a general inner hole measuring device cannot avoid interference of an external small hole to detect an inner ring groove is simply, conveniently and economically solved.

Description

Technical Field

[0001] The utility model relates to a precise measuring device for the inner diameter of a structural part, in particular to a device which can precisely measure the inner diameter of an inner large annular groove when the outer part is small and the inner part is large. Background Art

[0002] In the process of product design, there are often conflicts between functional requirements and processing technology and detectability. It is often impossible to take all requirements into account, and only the solution with better comprehensive evaluation can be selected for implementation. This will inevitably lead to a small number of structures that are difficult to detect. For example, a part is designed with a φ34H9 inner annular groove at a depth of 144mm. Figure 1 As shown in the figure, when machining the inner ring groove of such parts, the inner diameter of the ring groove is difficult to detect due to interference from the external small hole. Whether using a universal groove caliper, an inner diameter micrometer, or a three-dimensional coordinate measuring machine, it is impossible to implement detection. At present, the inner diameter of the ring groove can only be controlled by cutting test pieces, checking CNC programs, etc., which poses a serious quality risk. Utility Model Content

[0003] In order to overcome the problem that the common inner hole measuring device cannot detect the internal ring groove due to the inability to avoid the interference of external small holes, the utility model provides a deep ring inner diameter precision measuring device, which can not only accurately measure the diameter size of the conventional deep inner hole, but also can conveniently implement the precision measurement of the inner diameter of the ring groove deep inside the structure.

[0004] The utility model adopts the following technical scheme: a device for accurately measuring the inner diameter of a deep ring, comprising a fixed rod, a movable rod and a calibration gauge, wherein the fixed rod and the movable rod are connected to form an equal-arm lever mechanism through a rotating shaft, a probe is installed at the left end of the fixed rod, and a dial indicator is installed at the right end of the fixed rod through a fixed handle; a probe is installed at the left end of the movable rod, and the right end of the movable rod is in contact with the dial indicator head, a tension spring is installed between the fixed rod and the movable rod, and the calibration gauge is a special standard comparison ring for calibrating the zero position.

[0005] Furthermore, the fixed rod is a basic component of the device, and a guide groove is provided in the middle of the fixed rod to facilitate the movement of the movable rod.

[0006] Furthermore, the middle portion of the movable rod is located in the guide groove, and a handle is provided on the right side of the movable rod.

[0007] Furthermore, a limit screw is arranged between the handle and the fixed rod, and the limit screw serves to limit the maximum opening distance between the fixed rod and two probes installed at the left end of the movable rod.

[0008] Compared with the prior art, the utility model can effectively implement the precise measurement of the inner diameter of the deep inner ring, and simply and economically solves the problem that the general inner hole measuring device cannot avoid the interference of the external small hole to perform the internal ring groove detection. Its advantages are:

[0009] 1. Through the equal-arm lever mechanism composed of a movable rod, a rotating shaft and a fixed rod, the two probes can avoid interference from the small holes at the front end and smoothly enter the inner hole of the part to be tested;

[0010] 2. By setting the tension spring, the two probe measuring surfaces installed on the left end of the fixed rod and the movable rod are in contact with the inner groove of the workpiece, and the clearance of the rotating pair of the equal-arm lever mechanism is eliminated to provide appropriate measuring force;

[0011] 3. The movable rod rotates around the rotating shaft and pushes the dial indicator head, and the error value of the measured element can be directly displayed on the dial indicator. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0013] Figure 1 It is a schematic diagram of the tested part;

[0014] Figure 2 It is a schematic diagram of the structure of the utility model;

[0015] Figure 3 It is a cross-sectional structural schematic diagram of the utility model;

[0016] Figure 4 This is a schematic diagram of the inner hole detection of parts;

[0017] Figure 5 This is a measurement error analysis diagram of the utility model.

[0018] In the figure: 1. fixed rod, 2. movable rod, 3. limit screw, 4. fixed handle, 5. dial indicator, 6. tension spring, 7. rotating shaft, 8. measuring head, 9. calibration gauge, 10. guide groove, 11. handle. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in combination with the specific embodiments of the utility model and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] like Figure 2-3 As shown, a deep ring inner diameter precision measuring device of this embodiment includes a fixed rod 1, a movable rod 2, a limit screw 3, a fixed meter handle 4, a dial indicator 5, a tension spring 6, a rotating shaft 7, two measuring heads 8, and a calibration gauge 9;

[0021] The fixed rod 1 is the basic part of the device. A probe 8 is installed at the left end of the fixed rod 1. A guide groove 10 is opened in the middle to facilitate the movement of the movable rod 2. Another probe 8 is installed at the left end of the movable rod 2. The middle of the movable rod 2 is located in the guide groove 10. The movable rod 2 forms an equal-arm lever mechanism with the fixed rod 1 through the rotating shaft 7. The lever principle can avoid interference from the small hole at the end of the part.

[0022] The dial gauge 5 is an independent component, belonging to the general indicator gauge type measuring tool. A dial gauge or micrometer with different graduation values ​​can be selected according to the accuracy of the measured groove of the part; the dial gauge 5 is fixed to the right end of the fixed rod 1 through the fixed handle 4, and the dial gauge 5 head contacts the right end of the movable rod 2. When the relative distance between the two probes 8 at the left ends of the fixed rod 1 and the movable rod 2 changes slightly, the dial gauge 5 head is pushed through the equal-arm lever mechanism, and the change value can be indicated by the pointer;

[0023] A tension spring 6 is installed between the fixed rod 1 and the movable rod 2, and the two ends of the tension spring 6 are connected to the fixed rod 1 and the movable rod 2 respectively, so that the two probes 8 are opened up and down by a certain distance under the action of the tension spring 6, so that the two probes 8 are respectively in contact with the measured surface of the part, and at the same time, the clearance of the revolving pair of the equal-arm lever mechanism can be eliminated to provide a suitable measuring force;

[0024] A handle 11 is provided on the right side of the movable rod 2, and a limit screw 3 is provided between the handle 11 and the fixed rod 1, and the limit screw 3 serves to limit the maximum opening distance between the fixed rod 1 and the two probes 8 installed at the left end of the movable rod 2;

[0025] Calibration gauge 9 is a special standard comparison ring for calibrating the zero position of the device. Before using the device, the zero position of the dial indicator must be adjusted according to the nominal value of the measured inner diameter size.

[0026] Working principle:

[0027] Before use, Figure 2 and 3 As shown in the figure, the zero position of the dial indicator 5 is calibrated using the calibration gauge 9. When measuring the workpiece, Figure 4 As shown, first press down the handle 11 to reduce the distance between the two probes 8 and allow them to smoothly pass through the small hole at the front end of the part to reach the measured ring groove. At this time, the tension spring 6 is stretched; then release the handle 11, and the tension spring 6 contracts. Under the action of the tension spring 6, the measuring surfaces of the two probes 8 contact the inner surface of the part ring groove. At the same time, the movable rod 2 rotates around the rotating shaft 7 and pushes the dial indicator 5 head, and the error value of the inner diameter size of the measured ring groove is directly displayed on the dial indicator 5.

[0028] Measurement error analysis:

[0029] The measurement error caused by the manufacturing error of the device is extremely small and can be ignored for general precision measurements. The measurement error depends on the indication error of the selected scale. Figure 5 As shown in the figure, the influence of the manufacturing error of the device on the measurement accuracy is mainly that the distance from the rotation center of the fixed rod 1 and the movable rod 2 to the probe 8 and the distance from the rotation center to the dial indicator 5 head are not absolutely equal, so that when the probe 8 moves a small distance, it cannot be reflected 1:1 on the dial indicator 5 head. According to the design center distance deviation of 113±0.05mm, the maximum manufacturing center distance difference is 0.1mm. Assuming that the distance from the rotation center to the probe 8 is the minimum value of 112.95, and the distance from the rotation center to the center of the dial indicator 5 probe is the maximum value of 113.05, when the distance change between the two probes 8 is x, the movement of the dial indicator head is y=(113.05÷112.95)x=1.000885x. The maximum measurement error caused by manufacturing error is Δ=yx =1.000885xx=0.000885x. That is to say, even if the part error is 1mm, the maximum measurement error caused by the manufacturing error of the measuring device is less than 0.91%, which is negligible for part accuracy.

[0030] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A device for accurately measuring the inner diameter of a deep ring, characterized in that: The invention comprises a fixed rod (1), a movable rod (2), and a calibration gauge (9). The fixed rod (1) and the movable rod (2) are connected to form an equal-arm lever mechanism via a rotating shaft (7). A probe (8) is installed at the left end of the fixed rod (1), and a dial indicator (5) is installed at the right end of the fixed rod (1) via a dial indicator handle (4). The probe (8) is installed at the left end of the movable rod (2), and the right end of the movable rod (2) contacts the dial indicator (5). A tension spring (6) is installed between the fixed rod (1) and the movable rod (2). The calibration gauge (9) is a special standard comparison ring for zero position calibration.

2. A deep ring inner diameter precision measuring device according to claim 1, characterized in that: A guide groove (10) is provided in the middle of the fixed rod (1) to facilitate the movement of the movable rod (2).

3. A deep ring inner diameter precision measuring device according to claim 1 or 2, characterized in that: The middle portion of the movable rod (2) is located in the guide groove (10), and a handle (11) is provided on the right side of the movable rod (2).

4. A deep ring inner diameter precision measuring device according to claim 3, characterized in that: A limiting screw (3) is provided between the handle (11) and the fixing rod (1).

Images