CN104050327B - Method for designing low-pressure spraying head variable speed mechanism - Google Patents

Abstract

The invention relates to a method for designing a low-pressure spraying head variable speed mechanism. The method comprises the following steps of selecting an R33 spraying head of the Nelson company as a model machine, testing the spraying head, and measuring the 360-degree spraying range of the spraying head; calculating the range of the spraying head, and obtaining the range reduction rate delta of the spraying head; measuring the change relation between the rotating speed r and the range R of the spraying head, and obtaining the relation function R=f(r) between the rotating speed r and the range R; substituting the relation function R=f(r) into the formula of the range reduction rate delta, obtaining the reduction rate gamma of the rotating speed highest point r, finding out the change rule F1(r) of the rotating speed of the spraying head and the change rule F2(r) of the new rotating speed, and designing the combined scheme of a corresponding cam gear mechanism. A low-pressure spraying head variable speed cam mechanism is improved, under the new variable rotating speed rule, low-pressure spraying is even, and system energy saving is achieved.

Description

A kind of method for designing of low pressure shower nozzle variable speed mechanism

Technical field

The present invention relates to the key equipment of agricultural water-saving irrigation, a kind of variable speed mechanism of low pressure insufflation showerhead, especially A kind of method for designing of low pressure shower nozzle variable speed mechanism.

Background technology

Agricultural irrigation equipment is just towards the technique direction development of low-pressure energy-saving.In spray irrigation system, reduce the work pressure of shower nozzle Power can reduce system energy consumption, has preferable energy-saving effect.The rotating sprinkler applied in the market is varied, its In, the rotating sprinkler R33 model shower nozzle of Nelson company is according to there being sprinkling steady operation and other merits, good by users Comment.This shower nozzle has the characteristics that variable speed at work.Wherein variable speed mechanism is to be cooperated realization by cam and gear.

Found by experimental study, the rotating sprinkler R33 model shower nozzle of Nelson company, in rotation process, works as shower nozzle Operating pressure when being less than 150kPa, it is poor to spray uniformity, therefore, studies new shower nozzle variable speed rule, improves R33 model The uniformity that shower nozzle sprays under low pressure has critically important practical significance.And the structure realizing variable speed is cam mechanism, machine Structure is during shower nozzle rotation by the transmission speed of certain cyclomorphosis gear.Therefore, the present invention becomes to low pressure shower nozzle and turns Fast cam mechanism improves, and sums up a set of method for designing, has certain directive significance.

Through retrieval, there is presently no correlation declares patent.

Content of the invention

In order to overcome R33 model shower nozzle to spray the poor technical barrier of uniformity in the case of operating on low voltage, the present invention carries Supply a kind of design new method of the variable speed cam for R33 model shower nozzle, by the new variable speed rule of R33 model shower nozzle Change and spray uniformly come the low pressure to improve R33 model shower nozzle.

To achieve these goals, the present invention takes following technical scheme：A kind of low pressure shower nozzle variable speed mechanism sets Meter method, comprises the following steps：

A () selects the R33 model shower nozzle of Nelson company as model machine, shower nozzle is tested, and measurement shower nozzle sprays 360 The range of degree, respectively obtains in described sprinkler pattern range, maximum range is set to R₂, minimum range is set to R₁；

B () calculates to described sprinkler pattern range, obtain the range reduction rate δ of shower nozzle.Described range reduction rate δ calculates public Formula is：

$\mathrm{\δ}=\frac{R_2-R_1}{R_2}\×100\%---\left(1\right)$

In formula：R₂For maximum range, m；R₁For minimum range, m.

C () measures the variation relation of rotating speed of shower nozzle r and range R, obtain relation function R=f (r) of rotating speed r and range R= ar^b；

In formula：R is rotating speed, r/min；R is range, m；A, b are coefficient.

D () brings the formula (1) of the range reduction rate δ of described step (b) into relation function R=f (r) of described step (c) In, the computing formula obtaining the reduction rate γ of rotating speed peak r is：

$\mathrm{\γ}=\frac{{r_1}^b-{r_2}^b}{{r_1}^b}\×100\%---\left(2\right)$

In formula：r₂For minimum speed, r/min；r₁For maximum (top) speed, r/min.

E () adopts speed probe to measure one week 360 ° of rotation speed change of sprinkler rotation, computer gathers rotation speed change data, Data is fitted, obtains the Changing Pattern F of rotating speed of shower nozzle₁R ()=f (α), wherein, α is the anglec of rotation of shower nozzle.Described The Changing Pattern of rotating speed of shower nozzle is in 12 mechanical periodicity；

F (), according to step (e) and formula (2), finds out shower nozzle new rotation speed change rule F₂(r).Concretely comprise the following steps：1. will walk Suddenly in (e) rotary speed data of measurement average forFind out in cam mechanism simultaneouslyValue corresponding point M and point N； 2. willPart is recalculated, and formula (2) is brought intoIn partial function；3. sprayed New rotation speed change rule F of head₂(r).The Changing Pattern of described rotating speed of shower nozzle is in 12 mechanical periodicity；

G () is according to step (e) and (f), Curve guide impeller corresponding convex gear Mechanism Combination scheme.Concretely comprise the following steps：1. convex Wheel central shaft distance of shift cable before improving is to change to OA by OB to change to OC again, is a cycle, meets former shower nozzle and turn The Changing Pattern F of speed₁(r)；2. change the distance of shift cable before cam center wheelbase improves, the length of OA is reduced γ × (OA- OB), seamlessly transit 3 points of M, A, N simultaneously, make OB → OM → OA → ON → OC distance change rule meet Changing Pattern F₂(r)； 3. draw shift cable after improving, complete convex gear Mechanism Combination scheme.

It is an advantage of the current invention that：By campaign research and the calculating of the impact to range for the rotating speed, to low pressure shower nozzle The improvement of variable speed cam mechanism, provides a kind of method for designing of low pressure shower nozzle variable speed mechanism.Realize under new variable speed rule, Range change is less, and the radial direction water yield is more evenly distributed, and under different rotary angle, water-spraying amount difference is less, improves and sprays under low pressure Uniformity it is achieved that energy saving of system.

Brief description

Fig. 1 is the former Changing Pattern schematic diagram of rotating speed of shower nozzle.

Fig. 2 is the new change rule schematic diagram of rotating speed of shower nozzle.

Fig. 3 is shower nozzle convex gear structural representation before improvement.

Fig. 4 is shower nozzle convex gear structural representation after improvement.

In figure：1. gear external tooth, shift cable before 2. improving, 3. cam, shift cable after 4. improving.

Specific embodiment

The invention provides a kind of method for designing of low pressure shower nozzle variable speed mechanism.It is to allow above and other mesh of the present invention , feature and advantage can become apparent, hereafter, be described below in detail taking the R33 model shower nozzle of Nelson company as a example.

Choose the R33 model shower nozzle of Nelson company first as model machine, shower nozzle is tested, measurement shower nozzle sprays 360 degree of range, respectively obtains maximum range and is set to 12.5, minimum range is set to 8；Calculate shower nozzle range reduction rate δ be：

$\mathrm{\δ}=\frac{R_2-R_1}{R_2}\×100\%=36\%---\left(1\right)$

Measurement rotating speed of shower nozzle r and the variation relation of range R, obtain the relation function of rotating speed r and range R：

R=10.316r^-0.277(2)

Formula (2) is substituted in formula (1), the reduction rate γ obtaining rotating speed r peak is：

$\mathrm{\γ}=\frac{r_1-r_2}{r_1}\×100\%=79\%---\left(3\right)$

The Changing Pattern F of former rotating speed of shower nozzle₁R () is as shown in figure 1, the combination of corresponding convex gear is as shown in figure 3, cam center axle Before improving, the distance of shift cable is to change to OA by OB to change to OC again, is a cycle.

On this basis, one week 360 ° of rotation speed change of sprinkler rotation is measured using speed probe, computer gathers rotating speed Delta data, data is fitted, and obtains the Changing Pattern of rotating speed of shower nozzle Wherein, α is the anglec of rotation of shower nozzle.The Changing Pattern of described rotating speed of shower nozzle is in 12 mechanical periodicity.

By experiment measurement rotary speed data average forWillPart is entered Row recalculates, and formula (2) is brought intoIn partial function；Obtain shower nozzle new rotation speed change rule $F_2\left(r\right)=0.57+0.24\sin \mathrm{\π}\left(\frac{\mathrm{\α}-7.34}{15.06}\right).$

Curve guide impeller corresponding convex gear Mechanism Combination scheme.Concretely comprise the following steps：1. speed change before cam center wheelbase improves The distance of line is to change to OA by OB to change to OC again, is a cycle, meets the Changing Pattern F of former rotating speed of shower nozzle₁(r)；② Change the distance of shift cable before cam center wheelbase improves, the length of OA reduced by 79% × (OA-OB), seamlessly transit simultaneously M, 3 points of A, N, makes OB → OM → OA → ON → OC distance change rule meet Changing Pattern F₂(r)；3. draw shift cable after improving, Complete convex gear Mechanism Combination scheme.

According to formula (3), determine shower nozzle new rotation speed change rule F₂R () is as shown in Fig. 2 the change of described rotating speed of shower nozzle is advised Rule is in 12 mechanical periodicity；Curve guide impeller corresponding convex gear Mechanism Combination scheme, as shown in Figure 4.In work process, cam turns Dynamic, promote pinion rotation, gear and the internal tooth phase matching of shower nozzle, the rotating speed of shower nozzle is changed with this.

Rotating speed mechanism before and after improving is contrasted, is being all operating pressure 150kPa, during spacing 12m, after improvement Uniformity coefficient value is 74%, and former mechanism uniformity coefficient is 58%.Illustrate the double wedge turbine obtaining using the design method The low pressure that structure assembled scheme can effectively improve R33 model shower nozzle sprays uniformity.

Although the present invention is introduced as above with preferred embodiment, so it is not limited to the present invention, any this area skill Art personnel, without departing from the spirit and scope of the present invention, when being used for a variety of modifications and variations, the protection model of the therefore present invention Enclose to work as and be defined depending on the defined person of scope of the appended claims.

Claims (2)

1. a kind of method for designing of low pressure shower nozzle variable speed mechanism, comprises the following steps：

A () selects the R33 model shower nozzle of Nelson company as model machine, shower nozzle is tested, and measurement shower nozzle sprays 360 degree Range, respectively obtains in described sprinkler pattern range, maximum range is set to R₂, minimum range is set to R₁；

B () calculates to described sprinkler pattern range, obtain the range reduction rate δ of shower nozzle；Described range reduction rate δ computing formula For：

$\mathrm{\δ}=\frac{R_2-R_1}{R_2}\×100\%---\left(1\right)$

In formula：R₂For maximum range, m；R₁For minimum range, m；

C () measures the variation relation of rotating speed of shower nozzle r and range R, obtain relation function R=f (the r)=ar of rotating speed r and range R^b；

In formula：R is rotating speed, r/min；R is range, m；A, b are coefficient；

D () brings into relation function R=f (r) of described step (c) in the formula (1) of the range reduction rate δ of described step (b), obtain Computing formula to the reduction rate γ of rotating speed peak r is：

$\mathrm{\γ}=\frac{{r_1}^b-{r_2}^b}{{r_1}^b}\×100\%---\left(2\right)$

In formula：r₂For minimum speed, r/min；r₁For maximum (top) speed, r/min；

E () adopts speed probe to measure one week 360 ° of rotation speed change of sprinkler rotation, computer gathers rotation speed change data, by number According to being fitted, obtain the Changing Pattern F of rotating speed of shower nozzle₁R ()=f (α), wherein, α is the anglec of rotation of shower nozzle；Described shower nozzle The Changing Pattern of rotating speed is in 12 mechanical periodicity；

F (), according to step (e) and formula (2), finds out shower nozzle new rotation speed change rule F₂(r)；Concretely comprise the following steps：1. by step (e) The rotary speed data of middle measurement average forFind out in cam mechanism simultaneouslyValue corresponding point M and point N；2. willPart is recalculated, and formula (2) is brought intoIn partial function；3. obtain shower nozzle new Rotation speed change rule F₂(r)；

G () is according to step (e) and (f), Curve guide impeller corresponding convex gear Mechanism Combination scheme.

2. a kind of method for designing of low pressure shower nozzle variable speed mechanism according to claim 1 is it is characterised in that described step In (g), the concretely comprising the following steps of convex gear Mechanism Combination scheme：1. before cam center wheelbase improves, the distance of shift cable is to be become by OB Change and change to OC again to OA, be a cycle, meet the Changing Pattern F of former rotating speed of shower nozzle₁(r)；2. change cam center wheelbase The distance of shift cable before improvement, the length of OA is reduced γ × (OA-OB), seamlessly transits 3 points of M, A, N simultaneously, make OB → OM → OA → ON → OC distance change rule meets Changing Pattern F₂(r)；3. draw shift cable after improving, complete convex gear Mechanism Combination Scheme.