CN107621215A - Measuring method for fillet of pin shaft and measuring instrument adopting this method - Google Patents

Abstract

The invention discloses a method for measuring the fillet of a pin shaft and a measuring instrument using the method. A measuring tool with a sizing hole is used. The interference fit of the measuring pin shaft body is obtained by measuring the displacement of the round head of the pin shaft to be measured protruding into the sizing hole to obtain the value of the fillet, and the displacement and the fillet have a predetermined conversion relationship. Pin fillet measuring instrument, including base, gear system, rack and spring system, hole gauge, connector and displacement measuring device. Through the measuring method and the measuring instrument, the fillet of the pin shaft can be measured quickly and accurately.

Description

Measuring method for fillet of pin shaft and measuring instrument adopting this method

technical field

The invention relates to the technical field of contact measurement, in particular to a method for measuring a fillet of a pin shaft and a measuring instrument using the method.

Background technique

In the machinery industry, the interference fit of the shaft hole is widely used. In the design of the interference fit structure, the pin shaft is generally required to have a reasonable R angle (that is, the fillet of the pin shaft mentioned in this article). In actual production, whether the R angle of the pin shaft is qualified in the assembly process directly affects the difficulty and quality of assembly. At present, the measuring tools for quickly determining whether the R angle of the pin shaft meets the design requirements are mainly vernier calipers and R gauges. The vernier caliper can measure the maximum and minimum diameters at the R angle of the pin shaft. This method has low measurement accuracy due to the large influence of personnel; the R gauge based on the R angle profile can determine whether the R angle of the pin shaft meets the design requirements, but it cannot be accurate Measure the actual value of the R angle.

Contents of the invention

The present invention aims at the deficiencies of the prior art, and the technical problem to be solved is to provide a method for measuring pin shaft fillets and a measuring instrument using the method, through which the pin shaft fillets can be quickly and accurately measured.

The present invention solves the above-mentioned technical problems through the following technical solutions.

The pin fillet measurement method adopts a measuring tool with a sizing hole, the diameter of the sizing hole is for the round head of the pin shaft to be measured to extend into and interfere with the shaft body of the pin shaft to be measured, by measuring the The value of the fillet is obtained by measuring the displacement of the round head of the pin shaft protruding into the sizing hole, and the displacement and the fillet have a predetermined conversion relationship.

This measurement method combines the advantages of vernier calipers and R gauges, and can obtain accurate measurement values while realizing rapid measurement.

The pin fillet measuring instrument includes a base, a gear system, a rack spring system, a hole gauge, a connector and a displacement measuring device, the gear system and the hole gauge are positioned and installed on the base, the The rack spring system cooperates with the gear system to form the linear displacement of the rack through the rack and pinion meshing transmission. The connector is fitted with the rack and maintains synchronous displacement. The connector is provided with a pin shaft to be measured The matching crimping head, the hole gauge is provided with a sizing hole for the round head of the pin shaft to be tested to extend into and interfere with the shaft body of the pin shaft to be tested, and the rack spring system is preloaded The spring provides spring preload for the connector so that the crimping head passes through the sizing hole and maintains its position in the non-measurement state. Connect and make the round head of the pin shaft to be measured extend into the sizing hole, measure the linear displacement of the rack through the displacement measuring device, and obtain the value of the fillet through the conversion relationship between the predetermined linear displacement and the fillet.

Preferably, the bore gauge is provided with a stepped hole, the stepped hole includes an insertion hole and the sizing hole, and the insertion hole is in clearance fit with the shaft body of the pin shaft to be measured.

Preferably, the base is provided with a guide groove matched with the connector.

Preferably, the connector is a three-section stepped shaft, the left section of the shaft constitutes the crimping head, the right section of the shaft is connected to the rack, and the shaft diameter of the middle section of the shaft is larger than the diameter of the sizing hole. , the spring pre-tightening force provided by the pre-tightening spring makes the left shoulder of the middle section shaft and the end surface of the bore gauge on the same side as the sizing hole positioned in abutment.

Preferably, the right-section shaft is threadedly connected to the rack.

Preferably, the hole gauge is assembled from two separate components.

Preferably, the displacement measuring device is a pointer compass for measuring angular displacement, the gear system is equipped with the pointer compass, and the linear displacement of the rack is obtained by obtaining the readings of the pointer compass through a predetermined conversion relationship.

All in all, the pin shaft fillet measuring instrument of the present invention adopts a contact measurement design, which can amplify the tiny linear displacement of the rack through the gear system into a compass pointer reading that can be easily obtained, and overcomes the disadvantages of inaccurate measurement of common vernier calipers and R gauges. , the fillet size of the pin shaft can be measured more accurately, and the invention is beneficial to improving the assembly quality of the shaft hole interference fit in the machinery industry.

Description of drawings

Combining the following drawings is intended to facilitate the description of preferred embodiments, and does not constitute a limitation to the protection scope of the present invention.

Fig. 1 is the principle schematic diagram of pin shaft fillet measuring method of the present invention;

Fig. 2 is a schematic structural view of an embodiment of the pin fillet measuring instrument of the present invention;

FIG. 3 is a schematic diagram of a partially enlarged structure at point A in FIG. 2 .

In the figure: 1-base, 2-gear system, 3-rack spring system, 4-hole gauge, 5-connector, 6-pin shaft to be tested, 7-roller.

detailed description

In order to facilitate the understanding of the present invention, the present invention will be described in detail below in conjunction with the preferred embodiments of the present invention given in the accompanying drawings.

Fig. 1 schematic diagram of the embodiment principle of pin fillet measuring method of the present invention, the measuring tool with sizing hole is the roller 7 that internal diameter is determined, and the pin shaft 6 shaft body to be measured forms interference fit with roller 7, to be measured The contour of the round head on the left side of the pin shaft 6 is in contact with the edge of the inner hole on the right side of the roller 7. Based on the difference in the rounded corner of the round head of the pin shaft 6 to be tested (that is, the R angle mentioned in this article), the circle on the left side of the pin shaft 6 to be tested The distance from the end surface of the head to the left end surface of the roller 7 appears as a displacement change between L1 and L2, and the displacement and the fillet have a predetermined conversion relationship (this calculation relationship can be set in advance), so the measurement of the pin axis circle The size of the angle (R angle) can be converted into a numerical value for measuring displacement.

As shown in FIG. 2 , the pin fillet measuring instrument of the embodiment of the present invention includes a base 1 , a gear system 2 , a rack spring system 3 , a hole gauge 4 , a connector 5 and a displacement measuring device.

The gear system 2 and the hole gauge 4 are positioned and installed on the base 1. There are many ways to connect the gear system 2 to the base 1, and all designs with the same or similar functions belong to the within the protection scope of the present invention. The rack spring system 3 and the gear system 2 form a linear displacement of the rack through rack and pinion meshing transmission. The gear system 2 and the rack spring system 3 have many different structural designs and have the same function Or similar all design schemes also belong to the protection scope of the present invention.

The measuring function realized by the hole gauge 4 is the same as the measuring principle of the roller 7 . The bore gauge 4 is provided with a sizing hole for the round head of the pin shaft 6 to be measured to extend into and to interfere with the shaft body of the pin shaft 6 to be measured.

The connector 5 is fitted with the rack and maintains a synchronous displacement, and a guide groove matching the connector 5 can be optionally provided on the base 1 to assist the connector 5 to achieve precise orientation displacement , the connector 5 is provided with a crimping head matched with the pin shaft 6 to be tested. The rack spring system 3 provides a spring pre-tightening force for the connector 5 through a pre-tightening spring so that the crimping head passes through the sizing hole and maintains its position in a non-measurement state.

When measuring the fillet, the round head of the pin shaft 6 to be measured pushes the crimping head and makes the round head of the pin shaft 6 to be measured extend into the sizing hole, and the straight line of the rack is measured by a displacement measuring device The amount of displacement and the value of the rounded corners are obtained through the conversion relationship between the predetermined linear displacement and the rounded corners.

The displacement measuring device may be a pointer compass for measuring angular displacement. The gear system 2 is equipped with the pointer compass, and the linear displacement of the rack is obtained by obtaining the readings of the pointer compass through a predetermined conversion relationship. For example, since the tiny displacement of the rack can be introduced into the gear system 2, the multi-stage gears in the gear system 2 can amplify the tiny linear displacement of the rack into the rotation angle of the terminal gear (number of rotations) ), there is a definite mathematical relationship between the pointer compass reading and the rack displacement. If the enlarged measurement of the small linear displacement of the rack is replaced by a high-precision displacement sensor, it is also within the protection scope of the present invention.

As shown in Figure 3, the bore gauge 4 in this embodiment is provided with a stepped hole, and the stepped hole includes an insertion hole and the sizing hole, and the insertion hole is connected to the shaft body of the pin shaft 6 to be measured. The clearance fit not only plays an error-proof role in the model of the pin shaft to be tested, but also ensures the smooth insertion of the pin shaft 6 to be tested, thereby improving the measurement accuracy. When the processing technology of the stepped hole cannot meet the requirements, the hole gauge 4 can be set as two separate components to reduce the difficulty of processing, and then the coaxiality requirements can be guaranteed through the assembly process. This technical solution is also protected by the present invention within range.

An embodiment of the connector 5 as shown in Fig. 2, the connector 5 is a three-section step shaft, the left section shaft constitutes the crimping head, the right section shaft is connected with the rack, and the right section shaft It can be threadedly connected with the rack, or can be replaced by other methods such as interference fit, and all of them belong to the protection scope of the present invention. The shaft diameter of the middle section shaft is larger than the aperture of the sizing hole. In the non-measurement state, the spring preload provided by the pretension spring makes the left shoulder of the middle section shaft and the hole gauge 4 located at the The end face on the same side as the sizing hole is positioned against.

More specifically in conjunction with Fig. 2, the shaft diameter of the middle section shaft is much larger than the aperture of the sizing hole on the right side of the bore gauge 4, and the pretension spring in the rack spring system 3 is relatively large to the The connector 5 maintains a normal leftward spring force, and under the condition that the pin 6 to be tested is not inserted, the left shoulder of the connector 5 and the right end surface of the hole gauge 4 are positioned under the action of the spring force When the pin shaft 6 to be measured is inserted into the insertion hole of the hole gauge 4 and forms a rightward thrust to the connector 5, when the thrust is greater than the spring force, the connector 5 is displaced to the right until The R angle profile of the pin shaft 6 to be measured is in contact with the left edge of the sizing hole in the bore gauge 4, the pin shaft 6 to be measured can no longer be displaced to the right, and the connector 5 is no longer moving to the right. Right shift, read the reading of the compass pointer at this time, and determine the R angle through the shift value. As an example, the displacement and R angle comparison table shown in the following attached table 1 can be seen.

Schedule I

Several technical terms used in the present invention are only for convenience of description, and do not constitute a limitation to the present invention. Or adopt various modifications and modified implementations that can be equivalently replaced in the prior art, and all that are based on the spirit or technical concept of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. pin shaft fillet measuring method, it is characterized in that：Using the measurer with metering hole, the aperture of the metering hole supplies pin to be measured Axle round end is stretched into and is interference fitted with the bearing pin axle body to be measured, and the metering hole is stretched into by measuring the bearing pin round end to be measured Displacement obtain fillet numerical value, the displacement has predetermined conversion relation with fillet.

2. pin shaft fillet measuring instrument, it is characterized in that：Including pedestal, gear train, rack spring system, hole gauge, connector and position Measuring system, the gear train and the hole gauge positioning be installed on the pedestal, the rack spring system with it is described Gear train cooperatively forms the straight-line displacement of rack by rack and pinion engagement transmission, and the connector is equipped simultaneously with the rack Synchronous shift is kept, the connector is provided with the crimp head being engaged with bearing pin to be measured, and the hole gauge, which is provided with, supplies the pin to be measured Axle round end stretches into and is by preloading spring with the metering hole of the bearing pin axle body interference fit to be measured, the rack spring system The connector, which provides initial tension of spring, to be made the crimp head under non-measured state through the metering hole and is held in position, and is surveyed When measuring fillet, the bearing pin round end to be measured pushes the crimp head and the bearing pin round end to be measured is stretched into the metering hole, leads to Cross displacement measuring device and measure the straight-line displacement amount of the rack and by the conversion relation of predetermined straight-line displacement amount and fillet Obtain fillet numerical value.

3. pin shaft fillet measuring instrument according to claim 2, it is characterized in that：The hole gauge is provided with shoulder hole, the ladder Hole includes patchhole and the metering hole, and the patchhole coordinates with the bearing pin axle body to be measured for gap.

4. pin shaft fillet measuring instrument according to claim 2, it is characterized in that：The pedestal is provided with to match with the connector The guide groove of conjunction.

5. pin shaft fillet measuring instrument according to claim 2, it is characterized in that：The connector is three sections of Step Shafts, left section Axle forms the crimp head, and right section of axle is connected with the rack, and the diameter of axle of stage casing axle is more than the aperture of the metering hole, non-measured Under state, the initial tension of spring provided by the preloading spring makes the left side shoulder of the stage casing axle and being located at for the hole gauge The end face positioning of the metering hole homonymy reclines.

6. pin shaft fillet measuring instrument according to claim 5, it is characterized in that：The right section of axle connects with the rack for screw thread Connect.

7. pin shaft fillet measuring instrument according to claim 2, it is characterized in that：The hole gauge be two split components it is equipped and Into.

8. pin shaft fillet measuring instrument according to claim 2, it is characterized in that：Institute's displacement measurement device is measurement angular displacement Pointer compass, the gear train is equipped with the pointer compass, by obtaining the pointer compass reading through predetermined conversion The straight-line displacement amount of rack described in Relation acquisition.