CN208578599U - A kind of cam of camshaft blank after roughing - Google Patents

Abstract

The utility model discloses the cam of camshaft blanks after a kind of roughing, it has the machining allowance reserved for precision grinding process, it is characterized by: the machining allowance is set by the curvature variation of cam contour after fine grinding, the bigger region of curvature variation of the cam contour per adjacent δ, machining allowance is bigger, the angle position error of lobe blank when the δ is precision grinding process.The utility model carries out careful division by cam profile complexity to the machining allowance of fine grinding cam, the different cam profile bands of position, which are taken, reserves different fine grinding surpluses, reduce 30% to 50% or so than traditional uniform machining allowance, both ensure processing quality, surplus is significantly cut down again, it greatly reduced metal removal rate when fine grinding cam, to be obviously improved fine grinding cam efficiency and quality, reduce the loss of the fine grinding valuable cutter of cam simultaneously, reduces camshaft manufacturing cost to greatest extent.

Description

A kind of cam of camshaft blank after roughing

Technical field

The utility model relates to engine art, especially a kind of camshaft of engine.

Background technique

Camshaft is in-engine important spare part.Improve Camshaft Production efficiency, to reduce engine manufacturing cost, It improves Business Economic Benefit and competitiveness is significant.The cam contour of camshaft is complicated, and required precision is high, especially cam Surface quality (such as surface roughness, external waviness, molded line error etc.) requirement is very high, and fine grinding cam is that camshaft manufactures most Difficult and most challenge technique, is influence Camshaft Production efficiency, the key link of manufacturing cost.

The cam cutting process flow of camshaft is usually: the casting of 1. cam shaft blanks；2. being processed with techniques such as turnning and milling brills Each position of camshaft；3. roughing cam；4. cam face is heat-treated；5. refining the diameters of axle at different levels；6. refining cam.

By taking motorcycle single-cylinder four-stroke engine as an example, camshaft has two panels cam, and an IN cam, an EX is convex Wheel.The big portion's product of camshaft material is spheroidal graphite cast-iron or a small number of products are malleable cast iron.Roughing cam generally uses domestic number Cam milling machine is controlled, finishing cam generally uses import numerically-controlled cam grinder.

The machining allowance for refining cam is mainly determined by roughing cam profile accuracy, fine grinding cam tooling ability.Slightly Machining cam molded line precision specific manifestation are as follows: cam base circle bounce, cam base circle straightness, cam profile error, cam phase Angle error, cam face be coarse and all of above error, so the allowance for finish of cam is than simple optical axis allowance for finish Much bigger, the general machining allowance for refining optical axis is uniform, and usually unilateral 0.1 to 0.2, the machining allowance for refining cam is uniform, It is unilateral 0.2 to 0.4.At present in technique, since the machining allowance 3 ' at each position by rough machined lobe blank is equal It is even, as shown in Figure 1, after cam contour 1 ' and roughing between cam contour 2 ' being added for precision grinding process is reserved after fine grinding Spare time amount 3 ' is homogeneous phase etc., therefore the allowance for finish of cam is larger, to the fine grinding valuable cutter of cam --- CBN grinding wheel damages It consumes larger, causes production cost higher always.

Summary of the invention

In order to solve the problem above-mentioned, the utility model provides the cam of camshaft blank after a kind of roughing, utilizes Preset uneven machining allowance greatly reduces the machining allowance of fine grinding cam, reduces manufacturing cost.

Purpose of the utility model is realized as follows: the cam of camshaft blank after a kind of roughing, has for essence The reserved machining allowance of grinder sequence, it is characterised in that: the machining allowance is come by the curvature variation of cam contour after fine grinding Setting, the bigger region of curvature variation of the cam contour per adjacent δ, machining allowance is bigger, and the δ is convex when being precision grinding process Take turns the angle position error of blank.

The angle position error δ is 1 °~3 °.

To be unilateral at the machining allowance minimum be 0.10mm, maximum is unilateral 0.30mm.

The relationship of the machining allowance and curvature variation are as follows: Ai=A+kHi* ∣ ω ∣, wherein Ai is indicated more than any point Amount, A indicate that mill surplus is stayed on basis, and k is the proportionality constant no more than 1, and ω is curvature variation, and Hi is any point lift height.

The region of curvature variation ω=0, machining allowance is uniform, based on stay mill surplus.

The curvature variation ω is not zero but is the region of constant constant, and machining allowance is uniform.

The curvature variation ω is the region of the constant of variation, and machining allowance is uneven.

The A=0.10mm.

The k=0.58.

When the angle position error δ is 1 °, the region of curvature variation ω=0, machining allowance is uniform, is 0.10mm；The curvature variation ω be constant constant 0.04% region, machining allowance is uniform, for greater than 0.10 to 0.11mm；The curvature variation ω is the constant of variation and the region for being greater than > 0.04%, and machining allowance is greater than 0.10 To 0.3mm.

The utility model carries out careful division, different cams by cam profile complexity to the machining allowance of fine grinding cam The molded line band of position, which is taken, reserves different fine grinding surpluses, accurately realizes the cam after roughing by mathematical simulation equation The uneven machining allowance of axis cam blank is set, and reduces 30% to 50% or so than traditional uniform machining allowance, both really Processing quality is protected, and significantly cuts down surplus, greatly reduced metal removal rate when fine grinding cam, to be obviously improved Cam efficiency and quality are refined, while reducing the fine grinding valuable cutter of cam --- the loss of CBN grinding wheel reduces convex to greatest extent Wheel shaft manufacturing cost.

Detailed description of the invention

Fig. 1 is the lobe blank outline drawing after roughing in the prior art；

Fig. 2 is the lobe blank outline drawing after roughing of the utility model embodiment 1；

Fig. 3 is the angle of the lobe blank in precision grinding process of the lobe blank after roughing of the utility model embodiment 1 Spend position error；

Fig. 4 is the lifting curve figure of cam after the utility model embodiment 1 is refined；

Fig. 5 is curvature variation figure of the cam per adjacent 1 ° after the utility model embodiment 1 is refined.

Specific embodiment

The utility model is the cam of camshaft blank after a kind of roughing, is had more than the processing reserved for precision grinding process Amount, which set by the curvature variation ω of cam contour after fine grinding, both sides relation are as follows: cam contour Every adjacent δ ° of curvature variation ω bigger region, machining allowance is bigger, the angle of lobe blank when the δ is precision grinding process Spend position error.

The angle position error δ is the positioning of the deviation theory as caused by the tolerance of fixture, equipment and location dimension The differential seat angle of position, as shown in figure 3, dotted line therein is center line when lobe blank is located at theory orientation position, due to folder Tolerance existing for tool, equipment and location dimension etc., center line has with center line when theory orientation position when actual location position Deviation, the misalignment angle are angle position error δ.It is long using the acquisition units of angle position error δ as curvature variation ω Degree, the curvature variation ω are the change rate of often cam contour corresponding to adjacent δ °.For current equipment, general angle Position error δ is 1 °~3 °.

Preferably, depending on cam profile complexity, can preset be unilateral at machining allowance minimum is 0.10mm, most General goal is unilateral 0.30mm.

The relationship of the machining allowance and curvature variation are as follows: Ai=A+kHi* ∣ ω ∣, wherein Ai is indicated more than any point Amount, A indicate that mill surplus is stayed on basis, and k is the proportionality constant no more than 1, and ω is curvature variation, and Hi is any point lift height. Wherein, the lift height of cam certain point refers to distance of the cam orientation center to cam contour this point, the curvature of the position For the inverse of lift height.

The region of curvature variation ω=0, machining allowance is uniform, based on stay mill surplus.The curvature Change rate ω is not zero but is the region of constant constant, and machining allowance is uniform.The curvature variation ω is the constant of variation Region, machining allowance is uneven.

The present invention is by taking different fine grinding surpluses to set in cam profile different location region, thus with smaller Machining allowance realizes higher efficiency, higher quality and more inexpensive camshaft manufacture.

The utility model is further elaborated below by way of specific example combination attached drawing, but the utility model and unlimited In this specific examples.

Embodiment 1

As shown in Fig. 2, after fine grinding after cam contour 1 and roughing between cam contour 2 be for precision grinding process it is reserved Machining allowance 3.In the present embodiment, according to factors such as equipment, location dimension, fixtures, angle position error δ=1 °, basis is stayed It is 0.58 that mill surplus A, which takes 0.10mm, constant k,.

By the bigger region of adjacent every 1 ° of the curvature variation of lift, machining allowance 3 is bigger, as shown in Figure 4, Figure 5, according to Lifting curve can be divided into 3 big regions by change rate curve:

The area A: the region that curvature variation is 0, i.e. 263 °~47 ° of cam of region, machining allowance is uniform, is 0.10mm；

The area B: curvature variation is not zero but is the region of constant constant (0.04%), i.e. 49 °~90 °, 221 ° of cam ~263 ° of region, machining allowance is uniform, for slightly larger than 0.10mm but no more than 0.11mm；

The area C: the region of curvature variation linear change, i.e. 90 °~221 ° of cam, machining allowance are extremely slightly larger than 0.1mm 0.20mm, machining allowance is uneven in the region, and the more big then machining allowance of curvature variation is bigger.

Claims (10)

1. the cam of camshaft blank after a kind of roughing has the machining allowance reserved for precision grinding process, it is characterised in that: The relationship of the curvature variation of cam contour after the machining allowance and fine grinding are as follows: Curvature varying of the cam contour per adjacent δ The bigger region of rate, machining allowance is bigger, the angle position error of lobe blank when the δ is precision grinding process.

2. the cam of camshaft blank after roughing according to claim 1, it is characterised in that: the angle, which positions, to be missed Poor δ is 1 °~3 °.

3. the cam of camshaft blank after roughing according to claim 1, it is characterised in that: the machining allowance is most It is 0.10mm that small place, which is unilateral, and maximum is unilateral 0.30mm.

4. the cam of camshaft blank after roughing according to claim 1,2 or 3, it is characterised in that: the processing The relationship of surplus and curvature variation are as follows: Ai=A+kHi* ∣ ω ∣, wherein Ai indicates any point surplus, and A indicates that basis is stayed more than mill Amount, k are the proportionality constant no more than 1, and ω is curvature variation, and Hi is any point lift height.

5. the cam of camshaft blank after roughing according to claim 4, it is characterised in that: the curvature variation The region of ω=0, machining allowance is uniform, based on stay mill surplus.

6. the cam of camshaft blank after roughing according to claim 4, it is characterised in that: the curvature variation ω is not zero but is the region of constant constant, and machining allowance is uniform.

7. the cam of camshaft blank after roughing according to claim 4, it is characterised in that: the curvature variation ω is the region of the constant of variation, and machining allowance is uneven.

8. the cam of camshaft blank after roughing according to claim 4, it is characterised in that: the A=0.10mm.

9. the cam of camshaft blank after roughing according to claim 4, it is characterised in that: the k=0.58.

10. the cam of camshaft blank after roughing according to claim 4, it is characterised in that: the angle positioning When error delta is 1 °, the region of curvature variation ω=0, machining allowance is uniform, is 0.10mm；The Curvature varying Rate ω be constant constant 0.04% region, machining allowance is uniform, for greater than 0.10 to 0.11mm；The curvature variation ω Constant for variation and the region greater than > 0.04%, machining allowance are greater than 0.10 to 0.3mm.