Method for calculating depth of chamfer

Abstract

The application discloses a chamfer depth calculation method in the technical field of chamfer calculation, which comprises the following steps: 1, a mounting hole is formed on any workpiece, and the diameter d1 of the hole is selected as a specific value; the mounting hole is a circular hole, and the mounting hole is formed on the outer wall of the workpiece; a chamfer is needed at the opening of the mounting hole on the workpiece, the chamfer is a continuous chamfer with different sizes of a large chamfer and a small chamfer, the large chamfer, the small chamfer and the mounting hole are sequentially and continuously deep into the workpiece from the surface of the workpiece, the chamfer of the circular rod can be conveniently guided, the depth of the chamfer can be calculated according to the size of the mounting hole, the chamfer is conveniently machined, the chamfer depth which is more suitable for the chamfer angle is manufactured, and better assembly guiding and centering effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of chamfer calculation technology, and in particular to a method for calculating the depth of a chamfer. Background Technology

[0002] Chamfering refers to the machining process of cutting the edges of a workpiece into a certain bevel. Chamfering is used to remove burrs produced during machining and to facilitate assembly. It is generally done at the ends of parts.

[0003] The general purpose of chamfering is to remove burrs and improve aesthetics. However, chamfers specifically indicated on drawings are usually required by the installation process, such as for bearing installation guidance. Some rounded chamfers (or rounded transitions) can also reduce stress concentration and strengthen shaft parts. Furthermore, they facilitate assembly and are generally performed before the final machining is complete. When assembling parts, especially cylindrical fittings and the end faces of round holes, a chamfer of approximately 45° is often machined for ease of assembly. This chamfer serves as a guide during hammering and also makes assembling cylinders, shafts, or rods with round holes easier.

[0004] There are various forms of chamfering. On round rods or shafts, chamfering is generally done inward, meaning the chamfer is inclined towards the axis of the round rod. However, for round holes, chamfering is done outward to enlarge the hole and guide it during assembly.

[0005] Some chamfers require a two-stage chamfer. The first stage, with a larger chamfered hole, initially limits the position of the rod, making it easier to assemble with the chamfer. The rod is easily positioned on the outermost chamfer. Then, a second chamfer connects the first stage and the hole, further narrowing the chamfer area. This allows for a more refined chamfer, making it easier and more precise to guide the rod into the hole during assembly. This effectively reduces the risk of misalignment during small-clearance or interference fits. This is commonly seen in interference fits between shafts and holes, as interference fits are more difficult to assemble and require greater force. Precise guidance makes assembly easier. This two-stage chamfer allows for various angles and different diameters of mounting holes, each with a different chamfer depth. An excessively large chamfer depth results in an overly large mounting hole opening, and the chamfered hole's effect on shaft constraint is limited. Furthermore, excessively large chamfers are complex to machine. Conversely, an insufficiently small chamfer depth leads to unstable assembly guidance and is ineffective during assembly.

[0006] A single chamfer can lead to problems. An excessively large chamfer opening results in an excessively deep chamfer, reducing the effective fit and making machining difficult. Conversely, a small chamfer opening can cause assembly difficulties. Numerous examples exist of common 30° or 45° single chamfers causing assembly difficulties or product damage. Alternatively, using uncommon chamfer sizes for assembly purposes increases machining difficulty and cost. Therefore, a chamfer depth calculation method is needed to balance machining processes and production assembly, and to provide...

[0007] Based on this, the present invention designs a method for calculating the depth of chamfers to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide a method for calculating the depth of a chamfer, which can conveniently guide the chamfering of a round rod and calculate the appropriate chamfer depth based on the size of the assembly hole, facilitating the processing of the chamfer and thus creating a chamfer depth that is more suitable for the chamfer angle, achieving better assembly guidance and centering effects. Through a chamfer combination design, the chamfer is divided into a positioning section and a functional section, taking advantage of both. A larger chamfer is selected for guiding assembly, and a smaller chamfer is used for positioning and installation, so as to take into account both processing technology and production assembly, and to provide a method for calculating the chamfer depth.

[0009] This invention is implemented as follows: a method for calculating the depth of a chamfer, comprising:

[0010] Step 1: Open an assembly hole on any workpiece, and select the diameter of the hole as d1 as the specific value;

[0011] The assembly hole is a round hole and is located on the outer wall of the workpiece. The opening of the assembly hole on the workpiece needs to be chamfered. The chamfer is a continuous chamfer of different sizes, including large chamfer and small chamfer. The large chamfer, small chamfer and assembly hole extend continuously from the surface of the workpiece into the interior of the workpiece.

[0012] Step 2: When the rod aligns with the mounting hole, a pushing force is applied to the rod inside the mounting hole. The inserted rod is guided and constrained inward by the large and small chamfers, which are internal chamfers. The guiding force is directed towards the rod line of the mounting hole. The relationship between the pushing force and the large and small chamfers is obtained as follows:

[0013] The force on the large chamfer is: Fnet1 = cosβ × G - μ × sinβ × G;

[0014] The force on the small chamfer is: F_net2 = cosα × G - μ × sinα × G;

[0015] Wherein, G is the pushing force of the rod into the assembly hole, the large chamfer and the pushing force G form a resultant force F_result 1, the small chamfer and the pushing force G form a resultant force F_result 2, the angle between the large chamfer and the rod line of the assembly hole is set as β, and the angle between the small chamfer and the rod line of the assembly hole is set as α.

[0016] Step 3: Calculate the relationship between the thrust and resultant force and the angle by differentiating the function;

[0017] Differentiate the large chamfer resultant force Funified1 with respect to angle β, and differentiate the small chamfer resultant force Funified2 with respect to angle β;

[0018] We obtain the derivatives of Fnet with respect to α and β;

[0019] F ´ = -sinα(β)×G - 0.1×cosα(β)×G

[0020] From the above formula, we know that as either angle α or β increases, the net force F continuously decreases, and the decreasing trend of the net force F becomes increasingly stronger. Similarly, we can obtain...

[0021] Fcombined = -sinα×G - μ×cosα×G (0<α≤90)

[0022] From the above formula, we know that as the angle α increases, the net force F continuously decreases, and the decreasing trend of the net force F becomes increasingly stronger; angle β (0 < β ≤ 90).

[0023] Step 4: Calculate the relationship between the changes in angle and chamfer depth;

[0024] According to trigonometric functions:

[0025] d2 - d1 = 2 × h2 × tanα

[0026] △d = 2 × h² × tanα

[0027] Wherein, the depth of the large chamfer is h2, and the depth of the small chamfer is h1; the diameter of the assembly hole is d1, the maximum diameter of the large chamfer is d3, the minimum diameter of the small chamfer is d1, the minimum diameter of the large chamfer and the maximum diameter of the small chamfer are both d2, and Δd is the diameter difference between the large and small end faces of the large chamfer;

[0028] Step 5: From the functional relationship in Step 4, we know that relative to the large chamfer, the larger α is, the larger the pre-positioned diameter difference △d is.

[0029] The assembly performance of Fcombined and Δd is inversely proportional to α.

[0030] Similarly, relative to the small chamfer, the assembly performance of F_whole and △d is inversely proportional to β;

[0031] Step 5: Set α to a fixed value, and α is not the same as β;

[0032] Given the size of the assembly hole d1 and set the size of d3, determine the total chamfer depth H, where total depth H = h1 + h2;

[0033] Select an angle combination that is a combination of small chamfer angle β and large chamfer angle α;

[0034] ;

[0035] Calculate the value of h2, and then calculate the specific values ​​of h1 and h2 to obtain the depth dimensions of the large and small chamfers of the continuous chamfer.

[0036] Furthermore, the angle α of the larger chamfer within the same mounting hole is greater than the angle β of the smaller chamfer, and the values ​​of angles α and β are selected from 20°, 30°, 45° or 60°.

[0037] Furthermore, the assembly hole is a round hole, and d1 <d2<d3。

[0038] The beneficial effects of this invention are as follows: This invention no longer selects specific standard chamfer parameters, nor does it simply follow conventional chamfering methods. Instead, it calculates the appropriate chamfer depth based on the diameter of each assembly hole of different sizes and the selection of a suitable chamfer angle according to requirements. This results in a different chamfer depth for each assembly hole, making the chamfer's guiding properties more compatible with the assembly hole and angle. Furthermore, different chamfer depths can be calculated for different combinations of two-stage chamfer angles. The resulting assembly hole chamfers make shaft assembly easier and provide more precise guidance. Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 This is a schematic diagram of the chamfer distribution inside the assembly holes of the present invention;

[0041] Figure 2 This is a schematic diagram of the markings inside the assembly hole of the present invention;

[0042] Figure 3 This is a schematic diagram showing the force exerted on the assembly hole of the present invention during assembly.

[0043] The attached diagram lists the components represented by each number as follows:

[0044] 1-Large chamfer, 2-Small chamfer, 3-Assembly hole. Detailed Implementation

[0045] Please see Figures 1 to 3 As shown, the present invention provides a technical solution: a method for calculating the depth of a chamfer, comprising:

[0046] Step 1: Open an assembly hole 3 on any workpiece, and select the diameter of the hole as d1 as the specific value;

[0047] The assembly hole 3 is a round hole, and the assembly hole 3 is opened on the outer wall of the workpiece. The opening of the assembly hole 3 on the workpiece needs to be chamfered. The chamfer is a continuous chamfer of different sizes, namely large chamfer 1 and small chamfer 2. The large chamfer 1, small chamfer 2 and assembly hole 3 extend continuously from the surface of the workpiece to the interior of the workpiece.

[0048] Step 2: When the rod aligns with the mounting hole 3, a pushing force is applied to the rod inside the mounting hole 3. The inserted rod is guided and constrained inward by the inclined surfaces of the large chamfer 1 and the small chamfer 2. The large chamfer 1 and the small chamfer 2 are chamfers inside the hole, and the guiding force is directed towards the rod line of the mounting hole 3. The relationship between the pushing force and the large chamfer 1 and the small chamfer 2 is obtained as follows:

[0049] The force on the large chamfer 1 is: Fnet1 = cosβ × G - μ × sinβ × G;

[0050] The force on the small chamfer 2 is: F_net2 = cosα × G - μ × sinα × G;

[0051] Wherein, G is the pushing force of the rod into the assembly hole 3, the large chamfer 1 and the pushing force G form a resultant force F_result 1, the small chamfer 2 and the pushing force G form a resultant force F_result 2, the angle between the large chamfer 1 and the rod line of the assembly hole 3 is set as β, and the angle between the small chamfer 2 and the rod line of the assembly hole 3 is set as α.

[0052] Step 3: Calculate the relationship between the thrust and resultant force and the angle by differentiating the function;

[0053] Differentiate the resultant force Funified of the large chamfer 1 with respect to angle β, and differentiate the resultant force Funified of the small chamfer 2 with respect to angle β;

[0054] We obtain the derivatives of Fnet with respect to α and β;

[0055] F ´ = -sinα(β)×G - 0.1×cosα(β)×G

[0056] From the above formula, we know that as either angle α or β increases, the net force F continuously decreases, and the decreasing trend of the net force F becomes increasingly stronger. Similarly, we can obtain...

[0057] Fcombined = -sinα×G - μ×cosα×G (0<α≤90)

[0058] From the above formula, it can be seen that as the angle α increases, the resultant force F continuously decreases, and the trend of the decrease in the resultant force F becomes larger; the angle β (0 < β ≤ 90);

[0059] Step 4, calculate the variation relationship between the angle and the chamfer depth;

[0060] According to trigonometric functions:

[0061] d2 - d1 = 2 × h2 × tanα

[0062] △d = 2 × h2 × tanα;

[0063] Among them, the depth of the large chamfer 1 is h2, and the depth of the small chamfer 2 is h1; the hole diameter of the assembly hole 3 is d1, the maximum diameter of the large chamfer 1 is d3, the minimum diameter of the small chamfer 2 is d1, the minimum diameter of the large chamfer 1 and the maximum diameter of the small chamfer 2 are both d2, and △d is the diameter difference between the large and small end faces of the large chamfer 1;

[0064] Step 5, from the functional relationship in Step 4, it can be known that relative to the large chamfer 1, the larger the α, the larger the diameter difference △d of the pre-positioning;

[0065] Then the assembly performance of F combined and △d is inversely proportional to α;

[0066] Similarly, relative to the small chamfer 2, the assembly performance of F combined and △d is inversely proportional to β;

[0067] Step 5, set α as a fixed value, and α is different from β;

[0068] Given the size of d1 of the assembly hole 3, and set the size of d3, and then determine the total depth H of the chamfer, the total depth H = h1 + h2;

[0069] Select a set of angle values as the matching angle values of the angle β of the small chamfer 2 and the angle α of the large chamfer 1;

[0070] ;

[0071] Calculate the value of h2, and calculate the specific values of h1 and h2 to obtain the depth dimensions of the large chamfer 1 and the small chamfer 2 of the continuous chamfer.

[0072] Among them, the angle α of the large chamfer 2 in the same assembly hole 3 is greater than the angle β of the small chamfer 2, and the values of the angles α and β are one of the angle values selected from 20°, 30°, 45° or 60°. Select the appropriate angle for the diameter d1 of the assembly hole 3 to facilitate assembly, and then the chamfer depth and width can be calculated;

[0073] The assembly hole 3 is a round hole, and d1 < d2 < d3, ensuring that the chamfer guide is towards the inside of the assembly hole 3.

[0074] In a specific embodiment of the present invention:

[0075] This invention provides a method for calculating the depth of a chamfer. The technical problem encountered by this invention is as follows: 1. In the current assembly of holes and rods, regardless of the size of the assembly hole 3 and the round rod, the chamfer size is fixed unless specifically selected. Moreover, the depth of the chamfer is impossible to determine and is basically based on experience, selecting a fixed depth of 1mm or 2mm. When the diameter d1 of the assembly hole 3 is 20mm, the chamfer depth is 1mm, and when the diameter d1 of the assembly hole 3 is 200mm, the chamfer depth is 2mm, which is completely mismatched. However, there are no standard parameters for setting and processing, resulting in great assembly difficulty.

[0076] 2. Currently, the chamfer of assembly hole 3 is generally only one chamfer. When a two-stage chamfer is used, it is impossible to select a suitable chamfer depth. This two-stage chamfer requires continuous chamfering, precise guidance, convenient guidance, and appropriate depth. At present, it relies entirely on assembly processing experience to operate.

[0077] The technical problem solved by this invention is: to obtain the precise depth of the chamfer of the round rod and the round hole through accurate calculation, and to obtain the corresponding depth after selecting a specific angle, so as to adapt to different chamfers and hole sizes.

[0078] The technical effects achieved are as follows: 1. This invention no longer selects specific standard chamfer parameters, nor does it simply follow conventional chamfering. Instead, it calculates the appropriate chamfer depth and width based on the diameter of each assembly hole 3 of different sizes and the appropriate chamfer angle selected according to the requirements. This makes the chamfer depth of each assembly hole 3 different, so that the corresponding chamfer depths h1 and h2 can be obtained for different assembly hole diameters d1 and are adapted to the assembly hole 3.

[0079] 2. This method allows for the selection of different angle combinations based on assembly requirements. For example, the conventional 30° and 45° angles can be used, as well as 20° and 60° angles with special functions. 20° angles provide better centering and can also provide centripetal compression force during the guide installation process, such as when the drive shaft is installed into the differential and its retaining ring is compressed. 60° angles have a larger guiding range. When the assembly accuracy is high, using a large chamfer guide can effectively reduce the assembly difficulty.

[0080] This calculation method can better match the chamfer's guiding properties with the assembly hole 3 and the selected included angles α and β. Furthermore, it can calculate different chamfer depths for different combinations of two-stage chamfer angles. This process makes the chamfered assembly hole 3 easier to assemble and provides more precise guidance.

[0081] The technical solution in this invention is to solve the above problems, and the overall idea is as follows:

[0082] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0083] Select the shaft to be assembled with mounting hole 3. The material is steel. After the parts are coated with lubricating oil, the coefficient of friction is 0.1.

[0084] Step 1: A mounting hole 3 with a diameter of d1 needs to be opened on any workpiece. d1 is selected as a fixed value. The mounting hole 3 is a round hole and is opened on the outer wall of the workpiece. The opening of the mounting hole 3 on the workpiece needs to be chamfered. The chamfer is a continuous chamfer of different sizes, namely large chamfer 1 and small chamfer 2. Large chamfer 1, small chamfer 2 and mounting hole 3 are continuously extended from the surface of the workpiece to the interior of the workpiece.

[0085] Let β be the angle between the large chamfer 1 and the axis of the assembly hole 3, and let α be the angle between the small chamfer 2 and the axis of the assembly hole 3.

[0086] Step 2: When the shaft is aligned with the mounting hole 3, a pushing force G is applied into the axial mounting hole 3. The shaft inserted inward is guided by the large chamfer 1 and the small chamfer 2. The guiding forces of the large chamfer 1 and the small chamfer 2 are directed towards the axial direction of the mounting hole 3. The large chamfer 1 and the pushing force G form a resultant force F_result 1, and the small chamfer 2 and the pushing force G form a resultant force F_result 2.

[0087] The force on large chamfer 1 is: Fnet1 = cosβ × G - μ × sinβ × G.

[0088] The force applied to the small chamfer 2 is: F_net2 = cosα × G - μ × sinα × G;

[0089] Step 3: Differentiate the resultant force F_resultant1 of the large chamfer 1 with respect to angle β, and differentiate the resultant force F_resultant2 of the small chamfer 2 with respect to angle β;

[0090] And the derivatives of Fnet with respect to α and β are obtained;

[0091] ;

[0092] As can be seen from the above formula, as either angle α or β increases, the net force F continuously decreases, and the decreasing trend of the net force F becomes increasingly stronger.

[0093] Step 4, according to trigonometric functions, we know

[0094] d2 - d1 = 2 × h2 × tanα

[0095] △d = 2 × h² × tanα;

[0096] Among them, the depth of the large chamfer 1 is h2, the depth of the small chamfer 2 is h1; the diameter of the assembly hole 3 is d1, the maximum diameter of the large chamfer 1 is d3, the minimum diameter of the small chamfer 2 is d1, the minimum diameter of the large chamfer 1 and the maximum diameter of the small chamfer 2 are both d2, and △d is the diameter difference between the large and small end faces of the large chamfer 1.

[0097] Therefore, relative to the large chamfer 1, the larger α is, the larger the pre-positioned diameter difference Δd is;

[0098] The assembly performance of Fcombined and Δd is inversely proportional to α.

[0099] Similarly, relative to the small chamfer 2, the assembly performance of F and △d is inversely proportional to β;

[0100] That is, the larger the α angle, the easier it is to assemble; the larger the angle, the wider the guiding range, and the easier the guiding.

[0101] The larger β is, the wider the guiding range, and the easier it is to guide and align with the assembly hole 3.

[0102] The larger d1 is, the larger the hole diameter, the smaller the shaft, and the larger the clearance. The larger the clearance, the easier it is to assemble.

[0103] Step 5: Set α to a fixed value, and α is not the same as β;

[0104] Given the size of assembly hole 3 d1 and set the size of d3, determine the total chamfer depth H, where total depth H = h1 + h2;

[0105] Select an angle combination that is a combination of small chamfer 2 angle β and large chamfer 1 angle α;

[0106] The range of h1 is: 0 < h1 < (d3-d1) / 2 / tanα. ;

[0107] Where h1 takes values ​​in the range: 0 < h1 < (d3-d1) / 2 / tanα;

[0108] The value of h2 is calculated, and the specific values ​​of h1 and h2 are determined to obtain the depth dimensions of the large chamfer 1 and the small chamfer 2 of the continuous chamfer.

[0109] In mechanical design, taking gearboxes as an example, the chamfer depth is mostly in the range of 0~2mm. h2=1mm or 2mm is taken as the feature point. During assembly, △d is the pre-position. The larger the value of △d, the easier the assembly. △d is generally in the range of 2~4mm, which has good assembly tightness while maintaining a compact structure.

[0110] The angle α of the large chamfer 1 is greater than the angle β of the small chamfer 2. The values ​​of angles α and β are selected from 20°, 30°, 45° or 60°.

[0111] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for calculating the depth of a chamfer, characterized in that, Includes the following steps: Step 1: Open an assembly hole (3) on any workpiece, and select the diameter of the hole as d1 as the specific value; The assembly hole (3) is a round hole, and the assembly hole (3) is opened on the outer wall of the workpiece. The opening of the assembly hole (3) on the workpiece needs to be chamfered. The chamfer is a continuous chamfer of different sizes, namely a large chamfer (1) and a small chamfer (2). The large chamfer (1), the small chamfer (2) and the assembly hole (3) extend continuously from the surface of the workpiece to the interior of the workpiece. Step 2: When the rod is aligned with the assembly hole (3), a pushing force is applied to the rod inside the assembly hole (3). The rod inserted inward is guided by the inclined surfaces of the large chamfer (1) and the small chamfer (2), which are chamfers inside the hole. The guiding force is directed towards the rod line of the assembly hole (3). The relationship between the pushing force and the large chamfer (1) and the small chamfer (2) is obtained: The force on the large chamfer (1) is: Fnet1 = cosβ × G - μ × sinβ × G; The force on the small chamfer (2) is: F_net2 = cosα × G - μ × sinα × G; Wherein, G is the pushing force of the rod into the assembly hole (3), the large chamfer (1) and the pushing force G form a resultant force F_result 1, the small chamfer (2) and the pushing force G form a resultant force F_result 2, the angle between the large chamfer (1) and the rod line of the assembly hole (3) is set to β, and the angle between the small chamfer (2) and the rod line of the assembly hole (3) is set to α; Step 3: Calculate the relationship between the thrust and resultant force and the angle by differentiating the function; Differentiate the resultant force Funion1 of the large chamfer (1) with respect to angle β, and differentiate the resultant force Funion2 of the small chamfer (2) with respect to angle β; We obtain the derivatives of Fnet with respect to α and β; F ´ = -sinα(β)×G - 0.1×cosα(β)×G From the above formula, we know that as either angle α or β increases, the net force F continuously decreases, and the decreasing trend of the net force F becomes increasingly stronger; similarly, we can obtain... Fcombined = -sinα×G - μ×cosα×G (0<α≤90) From the above formula, we know that as the angle α increases, the net force F continuously decreases, and the decreasing trend of the net force F becomes increasingly stronger; angle β (0 < β ≤ 90). Step 4: Calculate the relationship between the changes in angle and chamfer depth; According to trigonometric functions: d2 - d1 = 2 × h2 × tanα △d = 2 × h² × tanα; Wherein, the depth of the large chamfer (1) is h2, and the depth of the small chamfer (2) is h1; the diameter of the assembly hole (3) is d1, the maximum diameter of the large chamfer (1) is d3, the minimum diameter of the small chamfer (2) is d1, the minimum diameter of the large chamfer (1) and the maximum diameter of the small chamfer (2) are both d2, and △d is the diameter difference between the large and small end faces of the large chamfer (1); Step 5: From the functional relationship in Step 4, we know that relative to the large chamfer (1), the larger α is, the larger the pre-positioned diameter difference △d is; The assembly performance of Fcombined and Δd is inversely proportional to α. Similarly, relative to the small chamfer (2), the assembly performance of F_combined and △d is inversely proportional to β; Step 5: Set α to a fixed value, and α is not the same as β; Given the size of d1 of the assembly hole (3) and the size of d3, determine the total depth H of the chamfer, where the total depth H = h1 + h2; Select an angle combination to form the combined angle values ​​of small chamfer (2) angle β and large chamfer (1) angle α; ； The value of h2 is calculated, and the specific values ​​of h1 and h2 are calculated to obtain the depth dimensions of the large chamfer (1) and small chamfer (2) of the continuous chamfer.

2. The method for calculating the depth of a chamfer according to claim 1, characterized in that: The angle α of the large chamfer (1) in the same assembly hole (3) is greater than the angle β of the small chamfer (2), and the values ​​of angle α and β are selected from 20°, 30°, 45° or 60°.

3. The method for calculating the depth of a chamfer according to claim 1, characterized in that: The assembly hole (3) is a round hole, and the d1 <d2<d3。

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