Gear spline pitch circle positioning device and positioning method

Abstract

A gear spline pitch circle positioning device and positioning method, the device includes a mounting stand, three measuring rods, three tapered blocks and a tapered mandrel. The small end of the tapered mandrel is inserted downward into the mounting hole of an assembly surrounded by at least three tapered blocks, and part of the outer conical surface of the tapered mandrel fits with the force element line of the inner surface of each tapered block, and the three measuring rods are pressed tightly into the spline tooth groove of the gear to be measured, so that the tapered mandrel, the tapered block, the measuring rod and the gear to be measured are assembled into an integrated structure. Gears of various specifications can be clamped by changing the up and down displacement of the tapered block and the tapered mandrel; and because the tapered block can move radially along the tapered mandrel, it makes up for the shortcoming that the traditional expansion mandrel cannot cooperate with the measuring rod to install and position the spline hole gear with the pitch circle. The device can cooperate with the measuring rod and the spline part of the gear to form a tooth surface positioning, and has strong versatility.

Description

Technical Field

[0001] The invention relates to the field of gear measuring and positioning devices, in particular to a gear spline pitch circle positioning device and a positioning method. Background Art

[0002] At present, there are two main ways to measure the single error of gears. The first is to use the gear measuring center; the second is to use the three-dimensional coordinate measuring machine for measurement. When measuring the gear in the gear measuring center, the gear must be inserted into the mandrel and installed on the top of the measuring center. The three-dimensional coordinate measuring machine is suitable for measuring large-module gears without mandrels. Gears measured by mandrels on the gear measuring center require mandrels of corresponding sizes for each type of mounting hole specification. After a batch of parts are measured, we need to make a large number of mandrels. There are two types of expansion mandrels on the market. One is the expansion mandrel with an adjustment margin within 0.02mm; the other is the expandable mandrel produced by Dongfeng Company. The smaller the mandrel specification, the smaller the adjustment range, for example: Ø9.525mm~ Ø12.7mm; the larger the specification, the larger the adjustable range, for example: Ø127mm~ Ø152.4mm. Due to structural limitations, this type of mandrel can only be installed on the gear with a light hole, and forms three lines of contact with the inner wall of the gear mounting hole. When measuring spline hole gears, spline pitch circle positioning should be used according to the product drawings. Since the pitch circle positioning mandrel is difficult to process and has high manufacturing costs, we need to design and manufacture a simple structure and method to achieve the measurement of such gear parts. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a gear spline pitch circle positioning device and positioning method, which utilizes a measuring rod and a gear smooth tapered core shaft with an adjustable amount and combines the method to meet the measurement versatility of gear parts with different specifications.

[0004] In order to achieve the above technical purpose, the adopted technical solution is: a gear spline pitch circle positioning device, comprising:

[0005] The mounting stand is used to place the gear to be measured, and a center hole of the stand is provided at the center thereof, which is smaller than the mounting hole of the gear to be measured, and the center hole of the stand is arranged corresponding to the mounting hole of the gear to be measured;

[0006] Three measuring rods are evenly arranged in the spline tooth groove of the gear being measured. The inner generatrix of the three measuring rods forms an envelope circle, the center of which is concentric with the spline pitch circle. To ensure the clamping accuracy, the measuring rods have certain roundness, cylindricity, straightness requirements and are wear-resistant. When the measuring rods are severely worn, replace the entire set of measuring rods;

[0007] Three cone blocks are placed in the mounting holes of the gear to be measured, each cone block is set close to a measuring rod, and the small end of the assembly formed by the three cone blocks is set downward, and the outer surface of each cone block is a cylindrical surface, and the inner surface thereof is a conical surface;

[0008] The tapered mandrel consists of a conical part in the middle and cylindrical parts at both ends. A top hole is provided on the end surface of the cylindrical part. The taper of the conical part is consistent with the taper of the inner surface of any cone block.

[0009] The small end of the tapered mandrel is inserted downward into the mounting hole of the assembly formed by three tapered blocks. The conical part of the tapered mandrel fits with the force element line of the inner surface of each tapered block, and the three measuring rods are pressed tightly into the spline tooth groove of the gear to be measured, so that the tapered mandrel, tapered blocks, measuring rods and gear to be measured are assembled into an integrated structure.

[0010] A positioning method for a gear spline pitch circle positioning device comprises the following steps;

[0011] Step 1: According to the size of the mounting hole of the gear to be tested, select a test stand whose center hole is smaller than the size of its mounting hole;

[0012] Step 2: Place the gear to be measured on the mounting stand, and place the mounting hole of the gear to be measured and the center hole of the stand so that they are visually concentric;

[0013] Step 3: Place the measuring rods evenly in the spline tooth grooves of the gear to be measured. The inner generatrix of the three measuring rods forms an envelope circle, the center of which is concentric with the spline pitch circle. Then place the small end of each cone block close to the measuring rod on the mounting stand at the lower center;

[0014] Step 4: Insert the small end of the tapered mandrel downward into the mounting hole of the gear to be measured surrounded by multiple tapered blocks until each measuring rod is in full contact with the spline tooth groove, and the tapered block element line on the inner surface of each tapered block at the force point of the radial line connecting the center point of the tapered mandrel and the center point of the measuring rod is in full contact with the tapered mandrel in the axial direction;

[0015] Step 5. Remove the entire positioning device consisting of the tapered mandrel, tapered block, measuring rod and gear to be measured from the mounting stand, turn it upside down and tap it lightly on the ground to allow gravity to lock the entire positioning device. The inner generatrix of the measuring rod forms an enveloping circle, the center of which is concentric with the pitch circle of the spline, thus achieving pitch circle positioning.

[0016] The cone block in step three is a cone block with a cylindrical exterior and a conical interior, and is cut from a cone ring that is matched with the conical part of the cone core shaft. The number of cone blocks selected is less than the number of cut blocks.

[0017] The cone block in step 3 needs to be inspected when used for the first time and during the process. The specific method of inspection is: first place the calibration ring gauge on the mounting stand, and the center of the calibration ring gauge is visually consistent with the center of the center hole of the mounting stand. Place each cone block with the small end at the bottom and radially evenly in the calibration ring gauge, and then insert the small end of the taper mandrel into the hole surrounded by multiple cone blocks at the bottom until it is tightened. Remove the entire set of inspection devices consisting of the calibration ring gauge, cone block, and taper mandrel from the mounting stand, knock it lightly on the ground in the opposite direction, let gravity lock the entire set of inspection devices, and measure the end face runout and circular runout of the calibration ring gauge. A cone block is qualified if it is less than 0.01mm. The calibration ring gauge is a ring gauge with roundness, cylindricity, straightness, coaxiality, and surface roughness requirements on both the inside and outside.

[0018] The beneficial effects of the present invention are as follows: a set of devices can clamp gears of various specifications by changing the up and down displacement of the tapered block and the tapered core shaft; and because the tapered block can move radially along the tapered core shaft, it makes up for the shortcoming that the traditional expansion core shaft cannot cooperate with the measuring rod to install and position the spline hole gear with the pitch circle. The device can cooperate with the measuring rod and the spline part of the gear to form tooth surface positioning, and has strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 It is a structural schematic diagram of the whole detection device of the present invention;

[0021] In the figure: 1. taper mandrel, 1-1. conical part, 1-2. cylindrical part, 2. taper block, 3. calibration ring gauge, 4. measuring rod, 5. gear to be measured, 6. mounting stand, 6-1. center hole of the stand. DETAILED DESCRIPTION

[0022] like Figure 1 As shown, a gear spline pitch circle positioning device includes a mounting stand 6, three measuring rods 4, three cone blocks 2 and a tapered mandrel 1. Usually, the appropriate measuring rod selected when measuring the span M value is such that the contact point of the measuring rod and the tooth groove is near the spline pitch circle. The measuring rod is close to the tooth surface, so when three appropriate measuring rods are evenly placed between the spline tooth grooves of the gear to be measured, the inner generatrix of the measuring rod forms an envelope circle, and the center of the envelope circle can actually coincide with the tooth centering, that is, the pitch circle positioning. When a smooth tapered mandrel with the same diameter as the envelope circle is selected and used in conjunction with the measuring rod, the tooth centering requirements can be met, thereby realizing the detection of spline hole parts. However, in order to meet the universality of different specifications of gear parts, the mandrel that cooperates with the measuring rod is required to have an adjustment amount.

[0023] The mounting stand 6 is used to place the gear 5 to be measured, and a stand center hole 6-1 smaller than the mounting hole of the gear 5 to be measured is provided at the center thereof. The stand center hole 6-1 is arranged corresponding to the mounting hole of the gear 5 to be measured, and the stand center hole 6-1 will not hinder the movement of the tapered core shaft when the tapered core shaft passes downward through the mounting hole.

[0024] Three measuring rods 4 are evenly arranged in the spline tooth grooves of the gear 5 to be measured. The inner generatrix of the three measuring rods 4 forms an envelope circle, and the center of the envelope circle is concentric with the spline pitch circle of the gear 5 to be measured. The measuring rods 4 are matched with the gear 5 to be measured, and matching measuring rods are used when positioning different gears to be measured.

[0025] Three cone blocks 2 are placed in the mounting holes of the gear 5 to be measured. The number of cone blocks 2 is consistent with the number of measuring rods 4. Each cone block 2 is set close to a measuring rod 4. The small ends of the three cone blocks 2 that form an assembly are set downward. The outer surface of each cone block 2 is a cylindrical surface, and the inner surface is a conical surface. The cone block cooperates with the conical part 1-1 of the tapered core shaft.

[0026] The tapered mandrel 1 is composed of a tapered portion 1-1 in the middle and cylindrical portions 1-2 at both ends. The center lines of the tapered portion 1-1 and the cylindrical portion 1-2 are the axes of the tapered mandrel 1. A top hole is provided on the end face of the cylindrical portion 1-2. The taper of the tapered portion 1-1 is consistent with the taper of the inner surface of any tapered block 2. During the processing of the tapered block 2, 70% of the contact surface within a certain length range of the large end portion of the tapered mandrel 1 is ground and processed. The inner surface stress element line of any tapered block 2 under stress is completely fitted with the outer surface of the tapered portion 1-1 of the tapered mandrel 1.

[0027] The small end of the tapered core shaft 1 is inserted downward into the mounting hole of the assembly formed by three tapered blocks 2. The conical part of the tapered core shaft 1 is in contact with the force element line of the inner surface of each tapered block 2, and three measuring rods 4 are pressed tightly into the spline tooth grooves of the gear 5 to be measured. The tapered core shaft 1, tapered blocks 2, measuring rods 4 and the gear 5 to be measured are assembled into an integrated structure. After the integrated structure is removed from the mounting stand and placed in the gear measuring center, single gear measurement can be performed.

[0028] The middle part of the tapered mandrel 1 is a tapered part, and the two ends are cylindrical. There are top holes on the end faces. When in use, it is installed on the upper and lower tops of the gear measuring center with the top holes. The taper of the tapered mandrel 1 is calculated according to the designed outer diameter change. The greater the change, the greater the taper. The cone block 2 is a cylinder on the outside and a cone on the inside. It is machined and matched with 70% of the contact surface within a certain length range of the large end of the tapered mandrel 1. The machined taper ring is cut into N blocks. The number of cone blocks used for positioning devices each time is 3, where N-3≥1. The cone blocks 2 are not connected to each other and can rotate radially and move axially along the tapered mandrel 1 so that the center of the cone block is basically in contact with the measuring rod.

[0029] In the current industry, the contact between the expandable mandrel with a large adjustment range and the light hole is line contact. It is in surface contact only when the outer diameter is consistent with the outer diameter of the slider within the adjustment range. When cooperating with the measuring rod to simulate the spline pitch circle positioning, it must always be the highest point contact. The number of teeth in the spline hole is not necessarily a number that can be divided by 3. In this case, the distribution of the measuring rods cannot ensure that the radial distance from the element line where the contact point is located to the axis of the tapered mandrel is consistent. Such positioning directly causes the circle formed by the contact points of multiple measuring rods and tooth grooves to be non-concentric with the spline pitch circle. The gear spline pitch circle positioning device involved in the present invention can increase the scope of use by changing the radial and axial relative positions of the split-flap cone block and the tapered mandrel, and always cooperates closely with the gear spline part to achieve the expansion effect.

[0030] When the tapered mandrel 1 is matched with the tapered block 2, when the outer diameter of the tapered mandrel 1 is relatively large, the tapered block has a step surface, and the outer diameter of the tapered mandrel 1 has a large adjustable range. When the outer diameter of the tapered mandrel 1 is small, the tapered block does not have a step surface. When in use, the tapered block contacts the measuring rod, and can move along the circumference to find the best contact point with the spline hole gear parts of different models and specifications. It relies on the self-locking of the parts by their own weight to closely match the gear parts, and has low manufacturing costs and high assembly accuracy. Each set of equipment is equipped with a calibration ring gauge with smooth inner and outer walls. The end face runout and circular runout of the calibration ring gauge are measured by installing it with the calibration ring gauge. The calibration ring gauge is qualified if it is less than 0.01mm. In order to facilitate installation, the corresponding installation stand is designed and manufactured according to the outer diameter adjustment amount of each set of positioning devices.

[0031] A positioning method for a gear spline pitch circle positioning device comprises the following steps;

[0032] Step 1: According to the size of the mounting hole (bright hole or spline minor diameter) of the gear to be measured, select a stand 6 whose center hole is smaller than the size of its mounting hole. The center hole of the stand 6 should not be too small to facilitate the downward insertion of the taper core shaft. The position between the center hole of the stand and the spline tooth groove of the gear to be measured should be able to place a stable measuring rod and a taper block.

[0033] Step 2: Place the gear to be tested on the mounting stand. Use the naked eye to make sure that the mounting hole of the gear to be tested is concentric with the center hole of the stand.

[0034] Step 3: Place the measuring rods evenly in the spline tooth grooves of the gear to be measured. The inner generatrix of the three measuring rods forms an envelope circle, the center of which is actually concentric with the spline pitch circle. Then place the small end of each cone block close to the measuring rod on the mounting stand at the lower center;

[0035] Step 4: Insert the small end of the tapered mandrel downward into the mounting hole of the gear to be measured surrounded by multiple tapered blocks until each measuring rod is in full contact with the spline tooth groove, and the radial distance from the straight line of the contact part of each tapered block and the measuring rod under stress to the center line of the tapered mandrel is consistent, that is, the circle formed by the straight lines of the three tapered blocks under stress is concentric with the tapered mandrel; Step 5: Remove the entire positioning device consisting of the tapered mandrel, tapered blocks, measuring rod and gear to be measured from the mounting stand, turn it upside down and tap it lightly on the ground to let gravity lock the entire positioning device, and the inner generatrix of the measuring rod forms an envelope circle, the center of which is concentric with the spline design datum and assembly datum pitch circle, that is, pitch circle positioning is achieved;

[0036] Step 6: Install the tapered mandrel 1 of the whole positioning device into the top of the gear measuring center through the upper and lower top holes for measurement;

[0037] Step 7. After the measurement, point the small end of the tapered mandrel of the positioning device downward and tap it on the ground, and the positioning device will loosen. When measuring different parts, choose the appropriate measuring rod and spline pitch circle positioning device according to the size of the spline pitch circle of the part.

[0038] The cone block in step three is a cone block with a cylindrical exterior and a conical interior, and is cut from a cone ring that is matched with the conical part of the cone core shaft. The number of cone blocks selected is less than the number of cut blocks.

[0039] like Figure 2 As shown, the cone block in step three needs to be tested when used for the first time and during the process. The specific method of testing is: first place the calibration ring gauge on the mounting stand, the center of the calibration ring gauge is consistent with the center of the center hole of the mounting stand, and each cone block is placed radially and evenly in the calibration ring gauge with the small end at the bottom, and then the small end of the taper mandrel is inserted into the hole surrounded by multiple cone blocks at the bottom until it is tightened, and the entire set of detection devices consisting of the calibration ring gauge, cone block, and taper mandrel are removed from the mounting stand, and the ground is knocked lightly in the opposite direction to let gravity lock the entire set of detection devices. The end face runout and circular runout of the calibration ring gauge are measured to be less than 0.01mm for qualified cone blocks. Only qualified taper mandrels 1 and cone blocks 2 can be used for positioning devices.

Claims

1. A positioning method for a gear spline pitch circle positioning device, the gear spline pitch circle positioning device comprising: A mounting stand (6) is used to place the gear to be measured (5), and a stand center hole (6-1) smaller than the mounting hole of the gear to be measured (5) is provided at its center, and the stand center hole (6-1) is arranged corresponding to the center of the mounting hole of the gear to be measured (5); Three measuring rods (4) are evenly arranged in the spline tooth grooves of the gear (5) to be measured, and the inner generatrixes of the three measuring rods (4) form an envelope circle, and the center of the envelope circle is concentric with the spline pitch circle of the gear (5) to be measured; Three cone blocks (2) are placed in the mounting hole of the gear (5) to be measured, each cone block (2) is arranged close to a measuring rod (4), and the small diameter end of the assembly formed by the three cone blocks (2) is arranged downward, and the outer surface of each cone block (2) is a cylindrical surface, and the inner surface thereof is a conical surface; A tapered mandrel (1) is composed of a conical portion (1-1) in the middle and cylindrical portions (1-2) at both ends, a top hole is provided on the end surface of the cylindrical portion (1-2), and the taper of the conical portion (1-1) is consistent with the taper of the inner surface of any cone block (2); The small diameter end of the tapered mandrel (1) is inserted downward into the mounting hole of the assembly surrounded by three tapered blocks (2), the conical portion of the tapered mandrel (1) is fitted with the inner surface force element line of each tapered block (2), and three measuring rods (4) are pressed tightly into the spline tooth groove of the gear (5) to be measured, so that the tapered mandrel (1), the tapered block (2), the measuring rod (4) and the gear (5) to be measured are assembled into an integrated structure; characterized in that: it includes the following steps; Step 1: According to the size of the mounting hole of the gear to be measured, select a mounting stand whose center hole is smaller than the size of the mounting hole of the gear to be measured (5); Step 2: Place the gear to be measured on the mounting stand, and place the mounting hole of the gear to be measured and the center hole of the stand so that they are visually concentric; Step 3: Place the measuring rods evenly in the spline tooth grooves of the gear to be measured. The inner generatrix of the three measuring rods forms an envelope circle, the center of which is concentric with the spline pitch circle. Then place the small diameter end of each cone block at the lower center close to the measuring rod on the mounting stand; Step 4. Insert the small diameter end of the tapered mandrel downward into the mounting hole of the gear to be measured surrounded by multiple tapered blocks until each measuring rod is in full contact with the spline tooth groove, and the tapered block element line on the inner surface of each tapered block at the force point on the line radially passing through the center point of the tapered mandrel and the center point of the measuring rod is in full contact with the tapered mandrel in the axial direction; Step 5. Remove the entire positioning device consisting of the tapered mandrel, tapered blocks, measuring rod and gear to be measured from the mounting stand, turn it upside down and tap it lightly on the ground to allow gravity to lock the entire positioning device, and the inner generatrix of the measuring rod forms an envelope circle, the center of which coincides with the concentricity of the spline, thereby achieving pitch circle positioning.

2. A positioning method for a gear spline pitch circle positioning device according to claim 1, characterized in that: The cone block in step three is a cone block with a cylindrical outer body and a conical inner surface, and is cut from a cone ring matched with a cone core shaft. The number of cone blocks selected is less than the number of cut blocks.

3. A positioning method for a gear spline pitch circle positioning device according to claim 1, characterized in that: The cone block in step three needs to be tested when it is used for the first time and during the process. The specific method of testing is: first place the calibration ring gauge on the mounting stand, and the center of the calibration ring gauge should be visually consistent with the center of the center hole of the mounting stand. Place each cone block with the small diameter end at the bottom and evenly radially in the calibration ring gauge. Then insert the small diameter end of the tapered mandrel at the bottom into the hole formed by multiple cone blocks until it is tightened. Remove the entire set of detection device consisting of the calibration ring gauge, cone block, and tapered mandrel from the mounting stand, tap it lightly on the ground in the opposite direction, let gravity lock the entire set of detection device, and measure the end face runout and circular runout of the calibration ring gauge. A cone block is qualified if it is less than 0.01mm.

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