Blind hole depth measuring tool

Abstract

The utility model relates to the technical field of machining precision measurement, in particular to a blind hole depth measuring tool, which comprises a shell, a dial gauge fixed at the top of the shell, and a measuring rod and a spring which are movably arranged in the shell, the shell is composed of a sleeve, an annular sealing plate and a fixing sleeve, the annular sealing plate is arranged at the top of the sleeve, and the fixing sleeve is arranged on the inner ring of the annular sealing plate and used for fixedly installing the dial gauge; two sections of guide rings matched with the inner diameter of the sleeve are arranged on the measuring rod, a measuring head of the measuring rod is exposed out of the sleeve, a positioning ring matched with the inner diameter of the blind hole is arranged on the measuring head, and a lightening hole penetrating through the measuring head is formed in the measuring rod; one end of the spring is connected with the annular sealing plate, and the other end abuts against the guide ring on the measuring rod; and a plurality of limiting screws are annularly arrayed between the two sections of guide rings on the sleeve and are used for preventing the measuring rod from sliding out of the sleeve. The utility model has the advantages of simple operation and high measurement precision, is convenient to replace the measuring rod to meet the measurement of blind holes of different specifications, and also meets the measurement of blind holes with central bosses at the hole bottoms.

Description

Technical Field

[0001] This utility model relates to the field of machining accuracy measurement technology, and in particular to a blind hole depth measuring tool. Background Technology

[0002] Existing blind hole depth measuring instruments are as per the instruction manual. Figure 2 As shown, the measuring instrument includes a housing 1 consisting of a cylindrical body 1a and an adjusting sleeve 1b screwed to the top of the cylindrical body; an indicator 2 fixed to the adjusting sleeve 1b; a measuring rod 3 disposed inside the cylindrical body 1a; and a spring 4 disposed on the flanges of the adjusting sleeve and the measuring rod. The bottom of the cylindrical body 1a has a positioning ring 1a.1 that matches the inner diameter of the blind hole, and the inner wall of the cylindrical body 1a has a guide ring 1a.2 for limiting the measuring rod 3. This existing measuring instrument has the following drawbacks:

[0003] 1. Since the blind hole positioning ring is located on the cylinder, when it is necessary to measure blind holes of different diameters and depths, this measuring tool cannot be used and a matching measuring tool needs to be used. Therefore, the adaptability of this measuring tool is low.

[0004] 2. When it is necessary to measure blind holes of different diameters, the cylinder body needs to be replaced. However, the cylinder body replacement operation of this measuring tool is troublesome, and the cost of making cylinder bodies of multiple specifications is also high.

[0005] 3. This measuring instrument relies solely on a thin guide ring on the cylinder for guidance, which can easily cause the measuring rod to swing during measurement, leading to measurement errors and affecting measurement accuracy.

[0006] 4. This measuring tool cannot meet the requirements of the attached document. Figure 1 Measurement of a blind hole with a central boss a at the bottom, as shown;

[0007] 5. The measuring tool itself is quite heavy, and its operation is time-consuming and laborious.

[0008] Based on this, this application provides a blind hole depth measuring tool with high measurement accuracy, simple operation, and more reasonable structural design, which facilitates the replacement of measuring rods to meet the depth measurement of blind holes of different specifications, and at the same time meets the measurement of blind holes with a central boss at the bottom. Utility Model Content

[0009] This utility model aims to solve the technical problems existing in the prior art. To this end, this utility model provides a blind hole depth measuring tool with high measurement accuracy, simple operation, and more reasonable structural design. It facilitates the replacement of measuring rods to meet the depth measurement needs of blind holes of different specifications, and also meets the measurement needs of blind holes with a central boss at the bottom.

[0010] The technical solution adopted by this utility model to solve its technical problem is:

[0011] A blind hole depth measuring instrument is provided, comprising a housing, an indicator fixed to the top of the housing, a measuring rod movably disposed within the housing, and a spring. The housing consists of a sleeve, an annular sealing plate, and a fixing sleeve. The annular sealing plate is disposed at the top of the sleeve, and the fixing sleeve is disposed within the inner ring of the annular sealing plate for fixing and mounting the indicator. The measuring rod has two guide rings that match the inner diameter of the sleeve, with its probe protruding from the sleeve. The probe has a positioning ring that matches the inner diameter of the blind hole. The measuring rod has a weight-reducing hole that penetrates the probe. One end of the spring is connected to the annular sealing plate, and the other end abuts against the guide ring on the measuring rod. The sleeve also has a plurality of limiting screws arranged in a ring between the two guide rings to prevent the measuring rod from slipping out of the sleeve.

[0012] In some alternative implementations, the housing is a one-piece molded structure.

[0013] In some alternative embodiments, the indicator is fixed to the retaining sleeve by a set screw.

[0014] In some alternative embodiments, the fixing sleeve is provided with multiple opening slots and a tapered external thread, and a locking nut is screwed onto the fixing sleeve, and the indicator is fixed to the fixing sleeve by the locking nut.

[0015] In some alternative implementations, the probe and the probe rod are integrally formed.

[0016] In some alternative implementations, the probe is threadedly connected to the probe rod.

[0017] In some alternative implementations, when the bottom of the blind hole is provided with a central boss, the inner diameter of the weight-reducing hole is larger than the diameter of the boss.

[0018] In some alternative embodiments, the outer wall of the sleeve is further provided with a flange that is coplanar with the bottom surface.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. The measuring tool designed in this utility model can be quickly removed by simply unscrewing the limit screw, which facilitates the quick replacement of the measuring rod to meet the measurement of blind holes of different specifications;

[0021] 2. A positioning ring matching the inner diameter of the blind hole is set on the probe. When it is necessary to measure blind holes of different diameters, only the probe rod needs to be replaced, and the measuring tool does not need to be replaced, which improves the applicability of the measuring tool.

[0022] 3. The measuring rod is guided by two guide rings, which effectively prevents the measuring rod from swinging during the measurement process and ensures measurement accuracy;

[0023] 4. The measuring rod is designed with a weight-reducing hole, which can reduce the weight of the measuring tool on the one hand, and also enable it to meet the measurement of blind holes with a central boss at the bottom of the hole, thus further improving the applicability of the measuring tool.

[0024] 5. The probe and probe rod are designed separately. When measuring blind holes of different specifications, only the probe needs to be replaced, which reduces the cost of accessories.

[0025] 6. The flange designed at the bottom of the cylinder increases the cylinder's adaptability to blind hole diameters, thus improving the applicability of the measuring tool. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0027] Figure 1 It is a cross-sectional view of the workpiece to be measured, which has a central boss at the bottom of the hole;

[0028] Figure 2 This is a schematic diagram of the structure of an existing blind hole depth measuring instrument;

[0029] Figure 3 This is a schematic diagram of the blind hole depth measuring instrument provided in Embodiment 1;

[0030] Figure 4 This is a zero-alignment state diagram of the blind hole depth measuring instrument provided in Embodiment 1;

[0031] Figure 5 This is a measurement status diagram of the blind hole depth measuring instrument provided in Embodiment 1;

[0032] Figure 6 This is a schematic diagram of the blind hole depth measuring instrument provided in Embodiment 2.

[0033] The attached diagram lists the components represented by each number as follows:

[0034] 1—Shell, 1a—Cylinder, 1a.1—Positioning ring, 1a.2—Guide ring, 1b—Adjusting screw sleeve, 1.1—Sleeve, 1.1.1—Flange, 1.2—Annular sealing plate, 1.3—Fixing sleeve, 2—Indicator, 3—Measuring rod, 3.1—Guide ring, 3.2—Measuring head, 3.2.1—Positioning ring, 3.3—Weight reduction hole, 4—Spring, 5—Locking nut, 6—Limit screw, 7—Base plate, 8—Standard ring, n—Central boss. Detailed Implementation

[0035] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0037] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0038] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0039] Example 1

[0040] This embodiment provides a blind hole depth measuring tool, as shown in the attached document. Figure 3 As shown, it includes a housing 1, an indicator 2 fixed to the top of the housing, a measuring rod 3 movably disposed within the housing, and a spring 4 for resetting the measuring rod. The indicator is a dial indicator or a micrometer. Details are as follows:

[0041] The housing 1 comprises a sleeve 1.1, an annular sealing plate 1.2, and a fixing sleeve 1.3, preferably a one-piece molded structure. The annular sealing plate 1.2 is located at the top of the sleeve 1.1, and the fixing sleeve 1.3 is located within the inner ring of the annular sealing plate 1.2, used to fix and install the indicator 2. In one embodiment, the indicator 2 is fixed to the fixing sleeve 1.3 by a set screw; in another embodiment, the fixing sleeve 1.3 has multiple opening slots and a tapered external thread, and a locking nut 5 is screwed onto the fixing sleeve 1.3, fixing the indicator 2 to the fixing sleeve 1.3 by the locking nut 5. This embodiment preferably uses a locking nut fixing installation method, which allows for quick assembly and disassembly of the indicator by manually loosening or tightening the locking nut.

[0042] The measuring rod 3 is provided with two guide rings 3.1 that match the inner diameter of the sleeve 1.1. The two guide rings guide the measuring rod, effectively preventing the measuring rod from swinging during the measurement process and ensuring measurement accuracy. The bottom of the measuring rod 3 is provided with a measuring head 3.2 (in this embodiment, the measuring head and the measuring rod are integrally formed). The measuring head 3.2 protrudes from the sleeve 1.1 and is provided with a positioning ring 3.2.1 that matches the inner diameter of the blind hole. In this embodiment, the positioning ring is set on the measuring head. When it is necessary to measure blind holes of different diameters, only the measuring rod needs to be replaced, without replacing the housing or measuring tool, which improves the applicability of the measuring tool. The measuring rod 3 is provided with a weight reduction hole 3.3 that penetrates the measuring head. When there is a central boss a at the bottom of the hole, the inner diameter of the weight reduction hole is larger than the diameter of the boss. The design of the weight reduction hole can reduce the weight of the measuring tool on the one hand, and also make it able to meet the measurement of blind holes with a central boss at the bottom of the hole, further improving the applicability of the measuring tool.

[0043] One end of the spring 4 is connected to the annular sealing plate 1.2, and the other end abuts against the guide ring 3.1 on the measuring rod 3;

[0044] The sleeve 1.1 is also equipped with a plurality of limiting screws 6 arranged in a ring between the two guide rings 3.1 to prevent the measuring rod from slipping out of the sleeve 1.1. This design allows the measuring rod to be removed quickly. In actual use, the measuring rod can be removed quickly by simply unscrewing the limiting screws, which facilitates the quick replacement of the measuring rod to meet the measurement of blind holes of different specifications.

[0045] For specific measurements, follow these steps:

[0046] 1. Zeroing the measuring instrument: as shown in the attached document. Figure 4 As shown, place the base plate 7 on a flat workbench, place the standard ring 8 which is consistent with the diameter and depth of the blind hole to be measured on the base plate, hold the housing of the measuring instrument, align the measuring rod of the measuring instrument with the standard ring, and press down on the measuring instrument to make the housing contact the standard ring. At this time, the pointer of the indicator is stabilized at a certain mark on the dial under the action of the measuring rod. Set the long pointer of the indicator to zero.

[0047] 2. Measuring parts: as shown in the attached document. Figure 5 As shown, place the blind hole part on a flat workbench, hold the housing of the measuring instrument, align the measuring rod of the measuring instrument with the blind hole of the part, press down on the measuring instrument until the housing contacts the upper surface of the part, look straight ahead at the indication value of the indicator, and judge whether the tolerance is within the allowable range. If it is within the allowable range, it is qualified; if it is not within the allowable range, it is unqualified.

[0048] Example 2

[0049] The only difference from Embodiment 1 is that this embodiment uses a separate design for the probe and the probe rod, as shown in the attached figure. Figure 3 As shown, the probe 3.2 is threadedly connected to the probe rod 3. In this embodiment, the probe and probe rod are designed as separate units. When measuring blind holes of different specifications, only the probe needs to be replaced, reducing the cost of accessories.

[0050] Example 3

[0051] Based on Example 1 or Example 2, as shown in the appendix Figure 3 To be continued Figure 6 As shown, the outer wall of the sleeve 1.1 is also provided with a flange 1.1.1 that is coplanar with the bottom surface. This design increases the adaptability of the sleeve to blind hole diameters and improves the applicability of the measuring tool.

[0052] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A blind hole depth measuring instrument, comprising a housing, an indicator fixed to the top of the housing, a measuring rod movably disposed within the housing, and a spring; characterized in that: The housing consists of a sleeve, an annular sealing plate, and a fixing sleeve. The annular sealing plate is located at the top of the sleeve, and the fixing sleeve is located on the inner ring of the annular sealing plate for fixing and installing the indicator. The measuring rod is provided with two guide rings that match the inner diameter of the sleeve. Its measuring head protrudes from the sleeve, and the measuring head is provided with a positioning ring that matches the inner diameter of the blind hole. The measuring rod is provided with a weight reduction hole that passes through the measuring head. One end of the spring is connected to the annular sealing plate, and the other end abuts against the guide ring on the measuring rod; The sleeve also has multiple limiting screws arranged in a ring between the two guide rings to prevent the measuring rod from slipping out of the sleeve.

2. The blind hole depth measuring instrument according to claim 1, characterized in that: The shell is a one-piece molded structure.

3. The blind hole depth measuring instrument according to claim 1, characterized in that: The indicator is fixed to the retaining sleeve by a set screw.

4. The blind hole depth measuring instrument according to claim 1, characterized in that: The fixing sleeve has multiple opening slots and a tapered external thread. A locking nut is screwed onto the fixing sleeve, and the indicator is fixed to the fixing sleeve by the locking nut.

5. The blind hole depth measuring instrument according to claim 1, characterized in that: The probe and the probe rod are integrally formed.

6. The blind hole depth measuring instrument according to claim 1, characterized in that: The probe is threadedly connected to the probe rod.

7. The blind hole depth measuring instrument according to claim 1, characterized in that: When the bottom of the blind hole being measured is provided with a central boss, the inner diameter of the weight-reducing hole is larger than the diameter of the boss.

8. The blind hole depth measuring instrument according to any one of claims 1 to 7, characterized in that: The outer wall of the sleeve is also provided with a flange that is coplanar with the bottom surface.

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