CN106767296B - A kind of pitch diameter of external thread measuring device - Google Patents

Abstract

The invention relates to the field of measuring instruments, in particular to an external thread pitch diameter measuring device. The external thread pitch diameter measuring device includes a measuring ruler and convex and concave measuring heads. The concave measuring head includes a measuring head seat. The measuring head seat is provided with first and second sliding claws. The first and second sliding claws cooperate with each other to form a The measuring tooth slot for clamping the threaded teeth, the measuring tooth slot includes first and second clamping surfaces for clamping the threaded teeth, the first clamping surface is arranged on the first sliding claw, and the second clamping surface is arranged on the first clamping surface. On the two sliding claws, the first and second sliding claws are guided and slidably matched with the measuring head seat, and the size of the measuring tooth slot can be adjusted by sliding the first and second sliding claws. For the measuring teeth set to fit with the thread groove, the external thread pitch diameter measuring device of the present invention can adjust the size of the measuring groove to be suitable for threads with different pitches, which solves the problem of measuring the current external thread pitch diameter measuring device. The problem that the measuring head needs to be replaced when the external thread of different pitch is required.

Description

An external thread pitch diameter measuring device

technical field

The invention relates to the field of measuring instruments, in particular to an external thread pitch diameter measuring device.

Background technique

The measurement of the pitch diameter of the existing external thread usually adopts the thread plug gauge, and the detection of the single pitch diameter of the existing thread plug gauge adopts the three-pin measurement method. Because the three-pin measuring instrument used in the three-pin measurement method has high precision, it is difficult to manufacture. , the price is high and cannot be repaired after wear, and the needle diameter deviation, the pitch of the tested piece, the half angle deviation, and the helix angle all affect the measurement results of a single pitch diameter. If these effects are eliminated, it is necessary to measure the deviation of each item first. In order to solve the above problems, the Chinese utility model patent with the announcement number of CN2248334Y and the announcement date of 1997.02.26 discloses the pitch diameter of a combined external thread pitch diameter comparator. The measuring device realizes the measurement of the outer diameter of the thread through the cooperation of the concave probe and the convex probe. The concave probe and the convex probe are made in pairs according to the thread pitch in the specification standard. A set of concave and convex probes cannot be used for more than one When measuring external threads with different pitches, it is necessary to replace different concave and convex probes, and the test efficiency is low.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an external thread pitch diameter measuring device to solve the problem that the measuring head needs to be replaced when measuring multiple sets of external threads with different pitches in the current external thread pitch diameter measuring device.

The technical scheme of the external thread pitch diameter measuring device of the present invention is as follows: the external thread pitch diameter measuring device comprises a measuring ruler and convex and concave measuring heads arranged oppositely on the measuring ruler, and the concave measuring head comprises a measuring head seat, a measuring head There are first and second sliding claws on the seat, and the first and second sliding claws cooperate with each other to form a measuring tooth slot for clamping the threaded teeth. The second clamping surface, the first clamping surface is arranged on the first sliding claw, the second clamping surface is arranged on the second sliding claw, and the first and second sliding claws are guided and slidably matched with the measuring head seat, The size of the measuring tooth slot can be adjusted by sliding the first and second sliding claws, and the convex measuring head is provided with measuring teeth paired with the measuring tooth slot for matching with the thread tooth slot.

The guiding directions of the measuring head base to the first and second sliding claws are respectively parallel to the first and second clamping surfaces.

The measuring head seat is provided with a first guide rail and a second guide rail, the first guide rail and the second guide rail are both guided and slidably assembled with a guide block, and the first sliding claw is connected to the guide on the first guide rail. The block is fixedly connected, the second sliding claw is fixedly connected with the guide block on the second guide rail, and the first and second sliding claws are guided and slid with the measuring head seat through the guide blocks on the first and second guide rails respectively. Matching, the measuring head seat is also provided with an adjusting device for adjusting the size of the measuring tooth slot. The adjusting device is connected with the guide block in a transmission and adjusts the size of the measuring tooth slot by driving the guide block to move.

The guide block is connected with a first elastic self-resetting device, the adjustment device comprises an adjustment screw threaded on the measuring head seat, and the guide block is connected with the adjustment screw in a driving manner.

The first sliding claw is provided with a first scale for measuring the size of the tooth slot.

The second sliding claw is provided with a second scale, the first and second scales are slidingly matched, and one of the first and second scales is the main scale of the sliding claw, and the other is the sliding claw. The claw vernier scale, the sliding claw main ruler and the sliding claw vernier scale constitute the vernier caliper mechanism.

The convex measuring head is provided with a V-shaped bracket which is used to be parallel to the radial plane of the thread to ensure that the connecting line of the convex and concave measuring heads passes through the diameter of the thread, and the angle bisector of the V-shaped bracket is connected with the two measuring heads. Coincidence, the V-shaped bracket is connected with the convex measuring head through the second elastic self-resetting device.

The second elastic self-resetting device is a spring used to move the V-shaped bracket back and forth along the connecting direction of the convex and concave measuring heads. One end of the spring is connected to the V-shaped bracket and the other end is connected to the convex measuring head.

The convex measuring head is provided with a guide hole, and the V-shaped bracket is provided with a guide rod that guides and cooperates with the guide hole along the connecting line direction of the convex and concave measuring heads.

The measuring ruler is a vernier caliper, and the vernier caliper is provided with a fixed claw and a moving claw, and the convex and concave measuring heads are respectively arranged on the fixed claw and the moving claw of the vernier caliper.

The beneficial effects of the present invention are as follows: the external thread pitch diameter measuring device of the present invention includes convex and concave measuring heads arranged on the measuring ruler, and the first and second sliding claws arranged on the measuring head seat of the concave measuring head pass through the first and second sliding claws. They cooperate with each other to form a measuring tooth slot for clamping the threaded tooth, and the convex measuring head is provided with a measuring tooth paired with the measuring tooth slot for close fit with the thread tooth slot, and the size of the measuring tooth slot can be adjusted by sliding the first tooth. 1. Adjustment of the second sliding claw, compared with the current external thread pitch diameter measuring device, the external thread pitch diameter measuring device of the present invention can adjust the size of the measuring tooth slot by sliding the first and second sliding claw, so as to be suitable for different The pitch of the thread solves the problem that the measuring head needs to be replaced when the current external thread pitch diameter measuring device measures external threads with different pitches.

Furthermore, the first and second sliding claws are guided and matched with the measuring head seat, and the guiding directions of the measuring head seat to the first and second sliding claws are respectively parallel to the first and second clamping surfaces, which can ensure the first clamping. The position of the intersection of the surface and the second clamping surface relative to the measuring ruler remains unchanged, and it is not necessary to re-zero when measuring threads with different pitches.

Furthermore, the measuring head seat is provided with the first and second guide rails, the guide rails are provided with guide blocks fixedly connected with the first and second sliding claws, and the guide blocks are connected with the first elastic self-resetting device and are connected with the adjusting device. In the transmission connection, the sliding adjustment of the guide block can be realized through the adjustment device and the first elastic self-resetting device, and the adjustment of the size of the measuring tooth slot can be realized through the sliding adjustment of the guide block, and the structure is simple and the operation is convenient.

Further, the first sliding claw is provided with a first scale, and the first scale can measure the size of the tooth slot through the change of the relative position of the first sliding claw and the second sliding claw. Knowing the value of the screw pitch, adjust the first scale so that the size of the measured tooth slot meets the requirements, and the operation is simple and convenient.

Further, one of the first and second scales is a sliding claw master ruler, and the other is a sliding claw vernier ruler. The vernier caliper mechanism provided can improve the accuracy of the measurement value. Further, the convex measurement The head is provided with a V-shaped bracket that is parallel to the radial plane of the thread to ensure that the connecting line of the convex and concave measuring heads passes through the diameter of the thread. The angle bisector of the V-shaped bracket coincides with the connecting line of the two measuring heads. When the circle is in contact with both sides of the V-shaped bracket, its diameter must be on the bisector of the V-shaped bracket. Since the angular bisector of the V-shaped bracket coincides with the connecting line of the two measuring heads, the connection between the two measuring heads can be guaranteed. The diameter of the thread through which the thread passes.

Description of drawings

1 is a schematic structural diagram of a specific embodiment of an external thread pitch diameter measuring device of the present invention;

FIG. 2 is a schematic diagram of the measurement principle of the concave measuring head and the convex measuring head in FIG. 1;

Fig. 3 is the enlarged view of B in Fig. 2;

Fig. 4 is the A-direction schematic diagram of the concave measuring head in Fig. 1;

Fig. 5 is the sectional view along C-C in Fig. 3;

FIG. 6 is a cross-sectional view along D-D in FIG. 3

Fig. 7 is the front view of the measuring head seat in Fig. 1;

Fig. 8 is the left side view of Fig. 7;

Fig. 9 is the top view of Fig. 8;

Figure 10 is a front view of the support block in Figure 1;

Fig. 11 is the left side view of Fig. 10;

Figure 12 is a front view of the V-shaped block in Figure 1;

Figure 13 is a left side view of Figure 12;

Fig. 14 is the structural representation of the top plate in Fig. 1;

Figure 15 is a front view of the measuring tooth in Figure 1;

Fig. 16 is the top view of Fig. 15;

FIG. 17 is a schematic structural diagram of the slider in FIG. 1;

Figure 18 is a left side view of Figure 17;

Fig. 19 is the structural representation of the guide rod in Fig. 1;

FIG. 20 is a schematic structural diagram of the first sliding claw in FIG. 1;

Figure 21 is a left side view of Figure 20;

Figure 22 is a left side view of Figure 21;

Figure 23 is a schematic structural diagram of the second sliding claw in Figure 1;

Figure 24 is a left side view of Figure 23;

Figure 25 is a left side view of Figure 24;

Figure 26 is a schematic diagram of the size of the 60-degree standard thread profile;

FIG. 27 is a comparison diagram of two sets of external thread pitch diameter measuring devices of the present invention measuring different pitches of threads to be measured.

Detailed ways

The embodiments of the present invention will be further described below with reference to the accompanying drawings.

A specific embodiment of a device for measuring the pitch diameter of an external thread of the present invention, as shown in FIGS. 1 to 27 , the device for measuring the pitch diameter of an external thread includes a measuring ruler 1 , a concave measuring head 2 arranged on the measuring ruler 1 , a convex The measuring head 3, the measuring ruler 1 is a vernier caliper, and the convex and concave measuring heads are respectively fixed on the fixed claw 11 and the moving claw 12 of the vernier caliper through positioning pins. In this embodiment, the concave measuring head 3 is arranged on the fixed claw 11 of the vernier caliper. , the convex measuring head 3 is arranged on the moving claw 12 of the vernier caliper. In other embodiments of the present invention, according to actual application requirements, the concave measuring head can also be arranged on the moving claw, and the convex measuring head is arranged on the fixed claw. . The concave measuring head 2 includes a measuring head base 21 , a first sliding claw 22 , a second sliding claw 23 , and an adjusting device 24 arranged on the measuring head base 21 to slide and guide the measuring head base 21 .

The measuring head base 21 is provided with a fixing arm 213 for fixedly assembling with the fixing claw 11 of the vernier caliper. The second guide rail, the first guide rail and the second guide rail are both guided and slidably assembled with guide blocks. In this embodiment, the first guide rail is the first guide long hole 211, the second guide rail is the second guide long hole 212, the first guide Guide blocks 26 are both guided and slidably assembled in the guide long hole and the second guide long hole, the first sliding claw is fixedly connected with the guide block in the first guide long hole, and the second sliding claw is connected with the guide block in the second guide long hole. In a fixed connection, the first and second sliding claws are guided and slidably matched with the measuring head seat through the guide blocks in the first and second guiding long holes respectively. One end of the first and second guide long holes are provided with countersunk holes 216 extending along the guide direction, and the side of the guide block 26 corresponding to the countersunk holes 216 in the first and second guide long holes is provided with spring mounting holes 261 , a compression spring 219 is arranged in the spring installation hole 261 , one end of the compression spring 219 is arranged in the spring installation hole 261 , and the other end is arranged in the counterbore 216 . The above-mentioned compression spring 219 constitutes a first elastic self-resetting device arranged at one end of the guide block. The first elastic self-resetting device and the adjusting device are respectively arranged at both ends of the guide block. The first elastic self-reset device provides the guide block with an elastic force to reset along the guide sliding direction of the guide block. In other embodiments, the above-mentioned compression spring can also be a tension spring provided at the other end of the guide block, and of course can also be other first elastic self-resetting devices such as elastic rubber. The guide block 26 is also provided with positioning pin holes 262 for locating the positions of the first and second sliding claws and threaded holes 263 for fixing the first and second sliding claws.

Both the first and second sliding claws include a fixed end and a clamping end arranged in the front-rear direction, the fixed end is arranged on the rear side of the clamping end, and the fixed ends of the first and second sliding claws are both provided for fixed connection with the guide block. The first and second sliding claws are relatively slidably matched at the clamping end to form a measuring tooth slot 25 for clamping the threaded tooth of the thread to be measured, and the measuring tooth slot 25 has first, The second clamping surface, the first clamping surface 221 is arranged on the clamping end 222 of the first sliding claw 22, the second clamping surface 231 is arranged at the clamping end 232 of the second sliding claw 23, and the first and second clamping surfaces The clamping ends of the sliding claws are all plate-shaped right-angled triangle structures. The external thread pitch diameter measuring device in this embodiment is suitable for measuring threads with a profile angle of 60 degrees. The two acute angles of the above-mentioned right triangle are 15 degrees and 75 degrees respectively. The first and second clamping surfaces are respectively the hypotenuses of two right-angled triangles, parallel to the line connecting the centers of the convex and concave measuring heads. The first and second sliding claws are fixed on the guide blocks in the first and second guide long holes.

The guiding direction of the first guiding long hole is parallel to the first clamping surface, and the guiding direction of the second guiding long hole is parallel to the second clamping surface. The angle between the first and second guide long holes is the same as the tooth profile angle of the thread to be measured. For threads with different tooth profile angles, different types of external thread pitch diameter measuring devices can be selected for measurement. In this embodiment, the thread to be tested is a 60-degree standard thread, and the angle between the first and second guide holes is 60 degrees. The included angle of the second guide hole can be adaptively changed.

The fixed end 223 of the first sliding claw 22 is provided with a first scale, the fixed end 233 of the second sliding claw 23 is provided with a second scale, the first scale is the main scale 224 of the sliding claw, and the second scale is The sliding claw vernier ruler 234, the sliding claw main ruler 224 and the sliding claw vernier ruler 234 form a vernier caliper mechanism, which improves the accuracy of the measurement value. When the zero scale lines of the first and second scales are coincident, the vertices of the 15-degree angles of the two right-angled triangles at the clamping ends of the first and second sliding claws are coincident, and the first and second scales are both aligned with the 15-degree angle of the right-angled triangle. The right-angled sides of an angle are perpendicular. In the process of measuring the pitch diameter of the thread, the first and second scales can read the relative displacement of the first and second sliding claws along the direction perpendicular to the connecting line of the convex and concave measuring heads. Adjust the size of the measured tooth slot according to the first and second scales to meet the requirements. The first and second scales are provided with sliding claw positioning holes and sliding claw fixing holes corresponding to the positioning pin holes 262 and threaded holes 263 on the guide block. Since the guiding direction of the first long guide hole is parallel to the first clamping surface, and the guiding direction of the second guiding long hole is parallel to the second clamping surface, when the first and second sliding claws are adjusted according to the pitch of the thread to be measured, the 1. The intersection of the first and second clamping surfaces on the second sliding claw is always in a fixed position, which ensures that the zero-scale lines of the first and second scales are always aligned, and does not need to be measured when measuring threads with different pitches. Repeat the zeroing of the first and second scales.

A first stop pin hole 225 and a second stop pin hole 235 are respectively provided on the rear end surfaces of the fixed ends of the first and second sliding claws, and stop pins are respectively provided in the first stop pin hole 225 and the second stop pin hole 235 27, a top plate 28 is also connected to the rear end surface, and the top plate 28 is provided with long holes 281 which are respectively matched with the two stop pins. The adjusting device 24 provided on the measuring head base 21 includes an adjusting screw 241 and a back cover 242 threaded on the boss on the measuring head base. One end of the adjusting screw 241 is pressed against the top plate 28, and the guide block can be driven through the top plate 28 26, and then adjust the size of the measuring tooth slot 25. When the adjusting screw is screwed in, the first and second sliding claws move forward along the guiding direction of the guide slot, and the size of the measuring tooth slot formed by the first and second sliding claws at the clamping end becomes larger. When the adjusting screw is unscrewed, Under the action of the compression spring 219, the first and second sliding claws move backward along the guiding direction of the guide slot, and the size of the measuring tooth groove formed by the first and second sliding claws at the clamping end becomes smaller.

The convex measuring head 3 includes a support block 31 that is fixedly connected with the moving claw 12 of the vernier caliper. The support block 31 is provided with a support block fixing hole 311 and a support block fixing groove 312 for fixed connection with the moving claw 12. Claw 32, one end of the measuring claw 32 is provided with a measuring tooth 321 for tightly fitting with the threaded tooth groove, and the other end is provided with a connecting rod 322 fixedly connected with the support block 31, and the support block 31 is provided with a fixed connection with the measuring claw 32 The measuring claw fixing hole 313. The measuring tooth has a first mating surface and a second mating surface for tightly fitting with the flank of the tooth groove of the thread to be measured.

In this embodiment, the thread to be tested is a 60-degree thread. In actual production, the 60-degree thread profile is formed by cutting off the top (H/8) and bottom (H/4) of the original equilateral triangle, as shown in the figure 26, according to the relevant dimensional analysis of the 60-degree thread: thread major diameter D, middle diameter D ₂ , minor diameter D ₁ , thread pitch P to be measured, ideal thread tooth height H:

D ₂ =D-3/4H;

D2 is approximately equal to D _- 0.6495P.

In order to make the measuring teeth adapt to different pitches, the range of the pitch P applicable to the measuring tool is set to be P ₁ -P ₂ , the ideal thread height H range is H ₁ -H ₂ , and the tip of the measuring tooth should be cut off at least H _2/4 , in addition, there is a certain machining error in the 60-degree thread in actual production. The thread top and tooth bottom are usually processed with a certain excessive rounded corner. In order to ensure that the measuring tooth can accurately measure the pitch diameter of the thread to be measured, the first 1. The second mating surface is in contact with the pitch diameter of the thread, and the cutting height of the tooth top of the measuring tooth should be less than H ₁ /2. In other embodiments, for non-standard threads to be tested and other standard threads to be tested, based on the above-mentioned principles, the height of the measured tooth crest can be adaptively changed.

To accurately measure the pitch diameter of the thread, it is necessary to ensure that the connecting line of the convex and concave measuring heads passes through the diameter of the thread to be measured, but it is difficult to pass the connecting line of the convex and concave measuring heads through the diameter of the thread during the actual operation. The support block 31 is provided with a V-shaped bracket 33 that is parallel to the radial plane of the thread to ensure that the connection line between the convex and concave measuring heads passes through the thread diameter. The angle bisector of the V-shaped bracket 33 coincides with the connection line of the two measuring heads, and The V-shaped bracket 33 includes two V-shaped supporting edges 331, and the connection of the two supporting edges is provided with a mounting hole 332 for being sleeved on the connecting rod 322 of the measuring claw 32. Between the V-shaped bracket 33 and the supporting block 31 A spring 34 is provided, and the spring 34 is a second elastic self-resetting device arranged between the V-shaped bracket 33 and the convex measuring head. In other embodiments, the second elastic self-resetting device can also be elastic rubber and other elastic self-resetting devices. device. A support edge 331 of the V-shaped bracket 33 is also provided with a guide rod fixing hole 333, a guide rod 34 is fixedly connected in the guide rod fixing hole, one end of the guide rod 34 is fixedly connected with the V-shaped bracket 33, and the other end is The guide holes 314 on the block 31 are slidably guided along the connecting direction of the convex and concave measuring heads, and the V-shaped bracket 33 always keeps a tendency to approach the measuring teeth 321 on the measuring claw under the action of the spring 34 . According to the principle of the V-shaped block, when the circle is in contact with both sides of the V-shaped block at the same time, the angle bisector of the V-shaped block coincides with the diameter of the circle. When the circle where the thread is located is in contact with both sides of the V-shaped bracket, its diameter must be On the angle bisector of the V-shaped bracket, the thread to be measured is in contact with both sides of the V-shaped block at the same time, and the operation is convenient. At the same time, the V-shaped block can slide back and forth relative to the measuring claw, and can adapt to different diameters of the thread to be measured. Since the angle bisector of the V-shaped bracket coincides with the connecting line of the two measuring heads, it can be ensured that the connecting line of the two measuring heads passes through the diameter of the thread.

The size of the measuring tooth slot on the concave measuring head of the external thread pitch diameter measuring device of the present invention can be adjusted, and the first and second scales can be used to set the measuring tooth slot of different sizes for the thread to be measured with different pitches. Measurement, no need to replace the measuring head, the operation is simple and convenient.

During assembly, the measuring head seat 21 and the support block 31 are respectively fixed on the two jaws of the vernier caliper through the positioning pins, the first sliding claw 22 is installed on the measuring head seat 21, and the guide block 26 is installed on the second guide The slotted hole 212 and the second sliding claw 23 are positioned by positioning pins and then fixedly connected with screws, and then the first sliding claw 22 is inserted between the second sliding claw 23 and the measuring head seat 21 and is connected to the first guide slot. The guide block in 211 is positioned by the positioning pin and then fixed and connected by the screw. One end of the compression spring 219 is installed in the countersunk hole 216, and the other end is installed in the spring installation hole 261 on the guide block 26. Under the action of the compression spring 219, the first and second sliding claws are always in the position of the measuring head seat 21. At one end, when the guide block 26 slides along the guide slot, the scales fixed on the two sliding claws also move relatively, and the size of the tooth slot can be read and measured according to the relative movement distance of the two scales. Next, fix the stopper pin 27 in the first and second stopper pin holes on the rear end surfaces of the first and second sliding claws, and then align the two long holes on the top plate 28 with the two stopper pins The top plate 28 is sheathed on the rear end surfaces of the first and second sliding claws, the back cover 242 is sheathed on the adjusting screw 241, and then the adjusting screw 241 is screwed on the measuring head seat 21 and the adjusting screw 241 is against the top plate 28. When the adjusting screw 241 is screwed in, the top plate 28 can be pushed to move, and then the top plate 28 drives the first and second sliding claws to move relatively. The size of the slot becomes larger. When the adjusting screw 241 is unscrewed, the first and second sliding claws retract under the action of the compression spring 219, and the size of the measuring slot 25 becomes smaller. When assembling the convex measuring head 3, put the V-shaped bracket 33 on the connecting rod 322 of the measuring claw 32 and set the spring 34 in the fixing hole 332 of the V-shaped bracket 33, and then fix the connecting rod 322 on the support block 31, At the same time, one end of the guide rod 34 is fixed on one side of the V-shaped bracket, and the other end slides and guides the guide hole 314 provided on the support block 31 along the connecting direction of the convex and concave measuring heads, and adjusts the connecting rod 322, the support block 31 and the spring. 34 so that the V-shaped bracket 33 is always subjected to a force in the direction of the measuring teeth 321 on the measuring jaws. The installation sequence of the concave and convex measuring heads can be selected according to the needs.

When using, first measure the pitch of the thread and rotate the adjusting screw to make the scale readings on the first and second sliding claws equal to the pitch of the thread, then tighten the back and place the thread to be measured between the convex and concave measuring heads, and push The moving claw of the vernier caliper makes the measuring tooth grooves of the first and second sliding claw and the measuring teeth on the measuring claw closely fit with the thread to be measured. At this time, the reading of the measuring ruler is the measured thread diameter.

Figure 27 is a schematic diagram showing the comparison of the measurement process of using two sets of the same size external thread pitch diameter measuring device of the present invention to measure two threads to be measured with different pitches, and the first step is to compare the measuring heads of the two sets of external thread pitch diameter measuring devices, In FIG. 27 , the pitch diameter line 1011 of the first thread to be tested 101 and the pitch diameter line 1021 of the second thread to be tested 102 are staggered.

In other embodiments of an external thread pitch diameter measuring device of the present invention, in order to realize that a set of measuring heads can measure external thread pitch diameters of different pitches, the above-mentioned first and second sliding claws may not be guided and matched with the measuring head seat. , and set a plurality of groups of first and second sliding claw installation positions on the measuring head seat, and different installation positions correspond to different pitches respectively. At this time, no adjustment device is provided; the above-mentioned first and second scales can also be omitted. When in use, the measuring tooth slot is corrected by using standard threads; the guiding directions of the first and second sliding claws and the measuring head seat may not be parallel to the first and second clamping surfaces. At this time, the measuring tooth slot formed by The intersection of the first and second clamping surfaces will change when the pitch of the thread to be measured is changed, and the pitch diameter of the external thread with different pitches can be measured by re-zeroing the first and second scales.

In addition, for the scales on the first and second sliding claws, the second scale may not be provided, only the first scale is provided on the first sliding claw, and the first scale passes through the first and second sliding claws. The relative position change of the second sliding claw measures the size of the tooth slot. At this time, in order to facilitate the reading, an indicator can be set on the second sliding claw, and the indicator is aligned with the zero scale of the first scale in the original state; the above scale It is also not necessary to directly display and measure the size of the tooth slot. The above-mentioned scale can be arranged on the first and second clamping surfaces or adjacent to the first and second clamping surfaces on the clamping ends of the first and second sliding claws. The first and second scales are arranged along the direction parallel to the first and second clamping surfaces.

In addition, for the guiding structure on the measuring head base that guides the first and second sliding claws, the above-mentioned first elastic self-resetting device may not be provided, and the first and second sliding claws are manually retracted; The above-mentioned first and second long guide holes can also be other guide rails such as guide straight grooves, guide rods, etc., and the guide blocks are correspondingly provided with corresponding guide structures; A hook structure can be provided at one end of the guide long hole, and one end of the compression spring can be fixed to one end of the guide long hole through a hook. The spring mounting hole on the above-mentioned guide block can also be replaced with a hook structure. At one end of the guide block and the guide long hole, the counterbore and the spring mounting hole may also be a boss structure matching the inner diameter of the compression spring.

In addition, for the V-shaped bracket on the convex measuring head, the spring between the above-mentioned V-shaped bracket and the support block may not be provided. At this time, both sides of the V-shaped bracket are hinged with the support block, and the second elastic self-resetting device is now The torsion spring is arranged between the two sides of the V-shaped bracket and the support block. Both sides of the V-shaped bracket are hinged with the support block through the torsion spring, so that the V-shaped bracket can adapt to the threads of different diameters to be measured; the guide fixed on the V-shaped bracket The rod may also not be provided, and can be adjusted manually during use; the above-mentioned V-shaped bracket can also be provided on the above-mentioned concave measuring head. The above-mentioned measuring ruler can also be a spiral micrometer, in which case the convex and concave measuring heads are respectively arranged on the two claws of the spiral micrometer.

Claims (8)

1. An external thread pitch diameter measuring device is characterized in that: it comprises a measuring ruler and a convex and concave measuring head that is relatively arranged on the measuring ruler, and the concave measuring head comprises a measuring head seat, and the measuring head seat is provided with a No. 1. The second sliding claws, the first and second sliding claws cooperate with each other to form a measuring tooth groove for clamping the threaded teeth, and the measuring tooth groove includes the first and second clamping surfaces for clamping the threaded teeth , the first clamping surface is arranged on the first sliding claw, the second clamping surface is arranged on the second sliding claw, the first and second sliding claws are guided and slidingly matched with the measuring head seat, and the measuring teeth The size of the groove can be adjusted by sliding the first and second sliding claws. The convex measuring head is provided with measuring teeth which are paired with the measuring tooth grooves and are adapted to the thread grooves; A first scale is provided for measuring the size of the tooth slot; the second sliding claw is provided with a second scale, and the first and second scales are slidably matched, and the first and second scales One of the two scales is the main sliding claw ruler, and the other is the sliding claw vernier scale. The sliding claw main scale and the sliding claw vernier scale constitute a vernier caliper mechanism; the range of the pitch P applicable to the measuring tool is P ₁ -P ₂ , ideally The range of thread height H is H ₁ -H ₂ , and the tip of the measuring tooth is cut off at least H ₂ /4. 2 . The external thread pitch diameter measuring device according to claim 1 , wherein the guiding directions of the first and second sliding claws by the measuring head seat are respectively parallel to the first and second clamping surfaces. 3 . 3. The external thread pitch diameter measuring device according to claim 2, wherein the measuring head seat is provided with a first guide rail and a second guide rail, and the first guide rail and the second guide rail are both guided A guide block is slidably assembled, the first sliding claw is fixedly connected with the guide block on the first guide rail, the second sliding claw is fixedly connected with the guide block on the second guide rail, the first and second sliding claw are fixedly connected with the guide block on the second guide rail. The sliding claw is guided and slidably matched with the measuring head seat through the guide blocks on the first and second guide rails respectively. The measuring head seat is also provided with an adjusting device for adjusting the size of the measuring tooth slot. The adjusting device is connected with the guide block and guided by the drive. The block movement adjusts the size of the measured cogging. 4 . The external thread pitch diameter measuring device according to claim 3 , wherein the guide block is connected with a first elastic self-resetting device, and the adjusting device comprises an adjusting screw threaded on the measuring head seat. 5 . , the guide block is connected with the adjustment screw in a transmission. 5. The external thread pitch diameter measuring device according to any one of claims 1-4, characterized in that: the convex measuring head is provided with a connection parallel to the radial plane of the thread to ensure that the convex and concave measuring heads are connected. The thread passes through the V-shaped bracket of the diameter of the thread, the angle bisector of the V-shaped bracket coincides with the connecting line of the two measuring heads, and the V-shaped bracket is connected with the convex measuring head through the second elastic self-resetting device. 6. The external thread pitch diameter measuring device according to claim 5, wherein the second elastic self-resetting device is a spring for making the V-shaped bracket move back and forth along the connecting direction of the convex and concave measuring heads, One end of the spring is connected with the V-shaped bracket, and the other end is connected with the convex measuring head. 7. The external thread pitch diameter measuring device according to claim 6, wherein the convex measuring head is provided with a guide hole, and the V-shaped bracket is provided with a guide hole along the convex and concave measuring heads. The wire direction guides the matching guide rod. 8. The external thread pitch diameter measuring device according to any one of claims 1-4, wherein the measuring ruler is a vernier caliper, and the vernier caliper is provided with a fixed claw and a movable claw, and a convex and concave measuring head They are respectively set on the fixed claw and the movable claw of the vernier caliper.