CN2238695Y - Sprocket hob - Google Patents

Abstract

The chain wheel hob belongs to a sleeve chain and roller chain wheel processing cutter. The cutter tooth block is arranged on the single-circle spiral surface along the outer circumference of the cutter body, the normal pitch of the cutter tooth block is equal to integral multiple of the pitch of the circular arc teeth of the chain wheel pitch and is larger than or equal to the maximum distance when the cutter tooth cuts into or cuts away from the tooth groove of the chain wheel; the minimum outer circle diameter of the hob is designed according to the maximum straightness tolerance value allowed by the axial section of the tooth root of the sprocket; the minimum cutter tooth number is designed according to the average cutting thickness allowed by the cutter teeth; the three numbers of the reference tooth shapes are only related to the pitch of the rack matched with the processed chain wheel and the outer diameter of the roller or the sleeve, and are not related to the tooth numbers of the chain wheel. The cutter has the outstanding advantages of high efficiency and universality.

Description

Sprocket hob

The utility model belongs to bush(ing) chain, roller chain wheel process tool.

The cutter that the sprocket wheel that processing and transmission are complementary with accurate bush(ing) chain, roller chain uses, i.e. sprocket hob.The cutting of bush(ing) chain, roller chain wheel gear teeth processing just is meant and uses this class cutter, on the general gear-hobbing machine of the sprocket wheel gear cutting machine of special use or repacking, the sprocket base is carried out cutting processing.

The gear cutting consideration commonly used of sprocket teeth is to use common sprocket hob to carry out gear hobbing processing on general gear hobbing lathe.Owing to be subjected to the restriction of lathe and hobboing cutter structure, the relative workpiece of hobboing cutter will have the radial feed of interruption and continuous axial feed motion man-hour adding, and the assisted machining time is long, and production efficiency is lower.

The purpose of this utility model is to provide a kind of efficient, the universal cutter of transmission with accurate bush(ing) chain, roller chain wheel series of products that can be used for processing.

Concrete technical scheme is said as follows in conjunction with the accompanying drawings:

Hobboing cutter and processed sprocket wheel are by the work of generating principle.Cutter returns continuously and circles, and the sprocket base is the angular interval of an adjacent sheaves of revolution continuously, and wherein each cutter tooth will excise the metal of different parts in tooth socket space of sprocket base successively continuously, finishes the flank of tooth processing of a gear teeth teeth groove.Because sprocket wheel facewidth b (42) size constancy and less, when hobboing cutter outside diameter d (10) size was big, cutter can not made axial feed motion.On the individual pen helical surface of cutter hub (3) circumferential periphery, can arrange more cutter tooth piece (1) simultaneously.Cutter also can not made radial feed like this, processes with minimal path.The reason that this is to use this hobboing cutter cutting to enhance productivity also is a basic foundation of determining this hobboing cutter main structure parameters.

Sprocket wheel for bush(ing) chain or roller chain with a kind of specification are complementary in certain range of numbers of teeth, all can adopt the universal sprocket hob of same specification to process, and sees Fig. 1 and Fig. 2.It is by cutter hub (3), cutter tooth piece (1) and clamping element---and trip bolt (2) is formed.Structurally its technical characterictic and usefulness are:

A. the cutter tooth piece (1) of hobboing cutter, mechanical fasteners on the individual pen helical surface of cutter hub (3), its normal direction pitch t ₀Equal the integral multiple of sprocket wheel pitch circle curved tooth distance, and more than or equal to cutter tooth incision, ultimate range L (23) when cutting off sprocket indentations, this is that cutter is realized the precondition that no radial feed moves:

B. the minimum outside diameter dmin (38) of hobboing cutter presses the maximum linear degree tolerance f that the sprocket tooth root axial section allows _Max(41) design promptly $d_{\min }=\frac{{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">b</figure-callout>}}^2}{4f_{\max }},$ B is the sprocket wheel facewidth (a 42) (see figure 4).Strengthen the outside diameter d of cutter, can reduce the straightness error of sprocket tooth root axial section, also can arrange more cutter tooth, not only help reducing the load of cutter tooth, also help reducing simultaneously the tooth surface roughness along cutter hub:

C. the minimum cutter tooth of this hobboing cutter is counted Z _MinPress the average thickness of cutting a that cutter tooth allows _cDesign, i.e. Z _Dmin= $\frac{h}{a_c}\&CenterDot;h$ Be sprocket wheel tooth depth (35);

D. the basic tooth profile of this hobboing cutter is identical with the basic tooth profile of general sprocket hob, its tooth profile parameter only with adapted chain pitch P, roller or sleeve outer diameter d ₁Relevant, have nothing to do with teeth number of sprocket Z, implemented the generalization principle of Tool Design.

Definite method of bush(ing) chain, roller chain wheel hobboing cutter structure and tooth profile parameter and computing formula are derived as follows:

One, cutter basic tooth profile parameter determines

The basic tooth profile of cutter is exactly a plane tooth bar profile of tooth, the sprocket wheel identical for adapted chain specification, that the number of teeth is different, all can with this plane tooth bar, realize the generating motion relation.The bush(ing) chain that adopts in the world, the basic tooth profile of roller chain wheel hobboing cutter have two kinds at present.The one, be the so-called three-arc profile of tooth (see figure 4) of fundamental mode with Unite States Standard (ANSI B291-86).The one, be the arc-straight line profile of tooth (see figure 3) of fundamental mode with DIN (DIN8197).A kind of profile of tooth advantage in back is more, application is general.Owing to when using generating to process sprocket wheel in certain range of numbers of teeth, will cause that the profile of tooth of processing sprocket wheel changes.Therefore tool-tooth profile must be through optimal design.Providing circular arc below---the computing formula of straight line tooth profile parameter is as follows.This computing formula is applicable to bush(ing) chain, the roller chain wheel of processing standard GB 1244-85 (being equivalent to IS0606-82) regulation.

p ₀＝1.0046p

h ₀＝0.265p＋0.5d ₁

α ₀＝24°

r ₀＝0.505d ₁

Wherein:

P-adapted chain pitch

d ₁-adapted chain roller diameter or sleeve outer diameter

p ₀-hobboing cutter basic tooth profile tooth pitch (14)

h ₀-hobboing cutter basic tooth profile tooth depth (19)

α ₀-hobboing cutter basic tooth profile profile angle (18)

r ₀-hobboing cutter basic tooth profile tooth top arc radius (15)

Two, the sprocket hob structural parameters determines

1. hobboing cutter normal direction pitch t ₀Determine

According to the basic principle of flank profil engagement, hobboing cutter normal direction pitch t ₀Should equal sprocket wheel pitch circle curved tooth distance is hobboing cutter basic tooth profile tooth pitch p ₀Integral multiple.

Be t ₀=p ₀K

Wherein, K is an integer, and its value depends on cutter tooth incision under the condition of no radial feed motion, the ultimate range L when cutting off sprocket indentations (23).

Under no radial feed moving condition, cutter tooth incision, the relation of the mutual alignment when cutting off sprocket indentations are seen Fig. 5.As seen from the figure, cutter incision end first tooth (44), its tooth top arc toothed (16) contacts at the C point with sprocket base outside circle (24).The P point is a working pitch point, and the B point is an end of engagement, and the N point is the path of contact initial point, and BPN is a path of contact.The cutter tooth incision is apart from t ₁(29), cut off distance (t ₂+ t ₃) (37+36), ultimate range L (23), and K value, can calculate by following formula respectively: $R_j=\frac{1.0046\&CenterDot;P\&CenterDot;\mathrm{<figure-callout\; id="2"\; label="Z"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">Z</figure-callout>}}{2\mathrm{\&pi;}}$ R _b＝R _j·cosα ₀ $t_1=\sqrt{{(R_a+r_0)}^2-{(R_f+r_0)}^2}$ ${\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">t</figure-callout>}}_2=(\sqrt{R_a^2-R_b^2}-\sqrt{R_j^2-R_b^2})\&CenterDot;\cos {\mathrm{\&alpha;}}_0$ ${\mathrm{<figure-callout\; id="3"\; label="t"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">t</figure-callout>}}_3=\frac{r_0}{\cos {\mathrm{\&alpha;}}_0}+(\sqrt{R_a^2-{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">t</figure-callout>}}_2^2}-R_f-r_0)\&CenterDot;{\mathrm{<figure-callout\; id="9"\; label="t"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">t</figure-callout>}}_9{\mathrm{\&alpha;}}_0$ L＝t ₁＋t ₂＋t ₃ $K=\frac{L}{P_0}$ (round numbers)

Wherein:

The Z-teeth number of sprocket

R _j-sprocket wheel pitch radius (32)

R _b-sprocket wheel base radius (31)

R _a-sprocket wheel radius of addendum (33)

R _f-sprocket tooth root radius of circle (34)

2. hobboing cutter outside diameter d's determines

Hobboing cutter outside diameter d (10) is more little, and when sprocket wheel facewidth b (42) one timings, the straightness error of sprocket tooth root axial section is big more.So minimum outside diameter d of hobboing cutter _Min(38), the maximum linear degree tolerance f that is permitted by the sprocket tooth root axial section _Max(41) design.As scheme shown in the b d _Min(38), b (42), f _Max(41) following geometrical relationship is arranged between the three: $d\min \&cong;\frac{{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="Y9620182300101.png"\; state="\{\{state\}\}">b</figure-callout>}}^2}{4\&CenterDot;f\max }$

Hobboing cutter outside diameter d (10) is big more, and cutter hub (3) can be arranged the quantity Z of cutter tooth _DJust many more, help reducing the cutter tooth load.Minimum cutter tooth is counted Z _Min, can be by under the no radial feed motion conditions, the average thickness of cutting a that cutter tooth allows _cCalculate: promptly $Z_{D\min }=\frac{h}{a_c}$

Wherein:

a _cThe average thickness of cutting that-cutter tooth allows, charcoal steel pitch is in 8～15.875mm scope in the processing, a _cBetween 0.10～0.15mm.

A-sprocket wheel tooth depth (35)

Hobboing cutter outside diameter d (10) is too big, and except that machining tool was restricted, also manufacturing brought difficulty to cutter.Therefore count Z satisfying above-mentioned minimum cutter tooth _MinAnd the maximum linear degree tolerance f of tooth root axial section permission _Max(41) under the prerequisite of Yao Qiuing, d (10) value should not be chosen excessive.Suggestion: between d=400～630mm.When adapted chain pitch P value is big, get big value.

The utlity model has following characteristics:

1. during owing to employing the utility model, can carry out machining to sprocket teeth with minimal path, thereby can significantly improve production efficiency.

2. identical for adapted chain specification, that the number of teeth is different bush(ing) chain, roller chain wheel series of products all can use a universal hobboing cutter processing, have fully implemented the generalization principle of Tool Design.

The utility model in small batches, in batch or under the mass production situation, all applicable.Be particularly useful in batch, large quantities of professional production fine pith sprocket wheel (occasion of p=8～15.875mm).

4. with the matching used sprocket wheel cutting of the utility model lathe, with general gear-hobbing machine contrast, transmission system is simple, lathe rigidity height, helps giving full play to the cutting usefulness of cutter.In addition, reequip general gear-hobbing machine, use this hobboing cutter to carry out cutting processing, also be relatively easy to.Description of drawings:

Fig. 1 is the sprocket hob front view.Wherein:

(1) is the cutter tooth piece; (2) be clamping element-trip bolt; (3) be cutter hub; (4) be the cutter installation base surface; (5) be the fastening counterbore of using of cutter; (6) for cutter taper hole is installed; (7) be hobboing cutter spiral angle of release; (8) be axial pitch; (9) be circle-dividing diameter; (10) be outside diameter.

Fig. 2 is the sprocket hob left view.Wherein:

(11) use screw for unloading the worker; (12) be side keyway; (13) be empty cutter district angle.

Fig. 3 sends out basic tooth profile () for sprocket wheel rolls.Wherein:

(14) be tooth pitch p ₀(15) be tooth top circular arc radius r ₀(16) be that tooth top is arc toothed; (17) be left and right sides flank straight line profile of tooth; (18) be profile angle α ₀(19) be tooth depth h ₀A is the arc toothed center of tooth top.

Fig. 4 is sprocket hob basic tooth profile (two).Wherein:

(20) be left and right sides flank arc toothed two; (21) be left and right sides flank arc toothed three; Q is the center of left and right sides flank arc toothed two; E is the center of left and right sides flank arc toothed three.

Fig. 5 is under the no radial feed motion conditions, and cutter tooth incision, the mutual alignment when cutting off the sprocket base concern schematic diagram.Wherein:

O is sprocket base center; P is a working pitch point; C is the contact point that the first tooth tooth top arc toothed (16) is held in sprocket base tip circle (24) and cutter incision; B is an end of engagement; N is the path of contact initial point; BPN is a path of contact; (22) return the sprocket indentations of back that circle for cutter by the cutter tooth generate; (23) under the no radial feed motion conditions, cutter tooth incision, the ultimate range L when cutting off sprocket indentations; (24) be chain wheel blank outside circle; (25) be cutter basic tooth profile nodel line; (26) be the sprocket wheel pitch circle; (27) be the sprocket wheel basic circle; (28) be the sprocket tooth root circle; (29) be the ultimate range t of incision end first tooth (44) away from node P ₁(30) be sprocket wheel pitch circle pressure angle, equal the profile angle a of cutter basic tooth profile ₀(18); (31) be sprocket wheel base radius R _b(32) be sprocket wheel pitch radius R _j(33) be chain wheel blank radius of addendum R _a(34) be sprocket tooth root radius of circle R _f(35) be sprocket wheel tooth depth h; (36) be cutter tooth size t ₃(37) for meshing the vertical range size t of B to OP line ₂(44) be cutter incision end first tooth; (45) cut off last cutter tooth for cutter.

Fig. 6 calculates the minimum outside diameter d of cutter _MinThe geometrical relationship schematic diagram.Wherein:

D is a center cutter; (38) be the minimum outside diameter d of cutter _Min(39) be sprocket wheel facewidth symmetry center line; (40) the sprocket tooth root axial section profile of processing for this cutter; (41) the maximum linear degree tolerance f that allows for the sprocket tooth root axial section _Max(42) be sprocket wheel facewidth b; (43) be the sprocket wheel axis.

Embodiment:

Number be that 0613 roller chain wheel is an example with machining chain below, illustrate how to press the formula that the utility model is derived, determine the structure and the tooth profile parameter of roller chain wheel hobboing cutter.

1. initial data

Chain title: roller chain

Chain number: 0613

Chain pitch: p=9.525mm

Roller diameter: d ₁=6.35mm

The range of numbers of teeth of sprocket wheel: z=9～120

The sprocket wheel facewidth: b=5.3mm

2. cutter basic tooth profile parameter

p ₀＝1.0046·p＝9.5688mm

h ₀=0.265·p-0.5·d ₁＝5.7mm

r ₀=0.505d ₁=3.21mm

α ₀=24°

3. determine cutter normal pitch t ₀Calculation procedure and result

Be example with the Z=60 tooth below, list result of calculation.

4. determine cutter outer circle diameter and cutter tooth number

According to the regulation of sprocket tooth form and tolerance GB (GB1244-85) and form and position tolerance GB (GB1184-80), the maximum linear degree tolerance f that the sprocket tooth root axial section allows _Max=0.03mm.So minimum outside diameter d of cutter _MinFor:

d _min＝b ²/4·f _max＝234mm

If get the average thickness of cutting a of cutter tooth _c=0.10～0.15mm does not then have under the radial feed motion conditions, and the required minimum cutter tooth of machining chain wheel tooth depth is counted Z _DminFor:

According to above-mentioned analysis, adopt inserted structure.See Fig. 1, Fig. 2.The cutter outside diameter is 500mm.On cutter hub, adorn 17 knife block (1), the every cutter tooth that 4 five equilibriums are arranged.Amount to 68 cutters tooth.On cutter hub, open sky cutter district, be used for workpiece loading and unloading.Empty cutter district's angle (13) equals a cutter tooth piece angle.Cutter hub amounts to 72 five equilibriums.

5. other structural parameters of this hobboing cutter can design with reference to universal cutter.This hobboing cutter manufacturing technology condition can be worked out with reference to gear hob general technical specifications (GB6084-85).

6. hobboing cutter range of application check

When machining chain tooth number Z not simultaneously, should test to the range of application of hobboing cutter by follow procedure.Below list part result of calculation.

Calculating shows, when teeth number of sprocket Z＞80, because of L＞t ₀(t ₀=47.8441), so the first cutter tooth thickness of cutting is too big during cutting, the height of several heavy-duty tool teeth is suitably revised before the reply for this reason, otherwise does not recommend to use.

When teeth number of sprocket Z in 9～22 scopes, less because of the L value, the real work cutter tooth is counted Z _DFew, so the thickness of cutting a of actual average _cGreater than permissible value, the cutter tooth load is heavier, should choose the Tool Design parameter for this reason again or adopt twice warp-wise feeding to process.

The optimal process range of numbers of teeth of this hobboing cutter is between 23～80.

Claims (3)

1. sprocket hob of being made up of cutter hub (3), cutter tooth piece (1) and clamping element-trip bolt (2) is characterized in that:

A. the mechanical clamping of cutter tooth piece (1) of this hobboing cutter is along on the individual pen helical surface of cutter hub (3) circumferential periphery, its normal direction pitch t ₀Equal the integral multiple of sprocket wheel pitch circle curved tooth distance, and more than or equal to cutter tooth incision, ultimate range L (23) when cutting off sprocket indentations;

B. the minimum outside diameter d of this hobboing cutter _Min(38) the maximum linear degree tolerance value f that allows by the sprocket tooth root axial section _Max(41) design, promptly $d_{\min }=\frac{b^2}{4f_{\max }},$ B is the sprocket wheel facewidth (42);

C. the minimum cutter tooth of this hobboing cutter is counted Z _DminPress the average thickness of cutting a that cutter tooth allows _cDesign, i.e. Z _Dmin= , h is sprocket wheel tooth depth (35);

D. the basic tooth profile parameter of this hobboing cutter is only outer through d with the processing sprocket wheel adapted chain pitch P of institute, roller or sleeve ₁Relevant, irrelevant with teeth number of sprocket Z.

2. by the described sprocket hob of claim 1, it is characterized in that: this hobboing cutter normal direction pitch t.Calculate by following formula respectively: $R_j=\frac{1.0046\&CenterDot;P\&CenterDot;Z}{2\mathrm{\&pi;}}$ R _b＝R _j·cosα ₀ $t_1=\sqrt{{(R_a+r_0)}^2-{(R_f+r_0)}^2}$ $t_2=(\sqrt{R_a^2-R_b^2}-\sqrt{R_j^2-R_b^2})\&CenterDot;\cos {\mathrm{\&alpha;}}_0$ $t_3=\frac{r_0}{\cos {\mathrm{\&alpha;}}_0}+(\sqrt{R_a^2-t_2^2}-R_f-r_0)\&CenterDot;t_9{\mathrm{\&alpha;}}_0$ L=t ₁+ t ₂+ t ₃K=L/P ₀(round numbers) t ₀=p ₀K

3. by the described sprocket hob of claim 1, it is characterized in that the basic tooth profile parameter of this hobboing cutter: tooth pitch p ₀(14), tooth depth h ₀(19), profile angle α ₀(18) and tooth item arc radius r ₀(15), calculate by following formula respectively:

p ₀＝1.0046·p

h ₀＝0.265·p＋0.5·d ₁

α ₀＝24°

r ₀＝0.505·d ₁

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