CN104791497A - Direct acting electric valve - Google Patents

Abstract

The invention discloses a direct acting electric valve. The direct acting electric valve comprises a valve base having a valve cavity, a motor arranged at the upper end of the valve base, and a lead screw, wherein a rotor of the motor is relatively fixed with the axial position of the valve base; the upper end of the lead screw is fixedly connected with the rotor; the lead screw is connected with a nut in a thread fit manner; the nut is connected with a valve core; the valve core is driven by the nut to axially move to open or close a valve port formed in the valve base; a spring is arranged between the nut and the valve core; the valve core is located in a total closing state; the valve core is tightly sealed with the valve port under the effect of the spring; and the lower end of the nut is bonded with the valve core. Through the design, when the failure of the axial locking force transferred to the nut and the valve core by the motor through the lead screw due to the slippage of transmission threads of the lead screw and the nut caused by vibration or other factors is generated, the valve core can be tightly pressed on the valve port through the elastic force of the spring to prevent leakage.

Description

A kind of direct-driven motor-operated valve

Technical field

The present invention relates to fluid control component technical field, particularly relate to a kind of direct-driven motor-operated valve.

Background technique

The business air conditioner such as multi-connected machine or module machine, a multiple indoor set system of outdoor unit UNICOM, the refrigerant loop of each indoor set all needs install flow control valve, for cutting off refrigerant or adjust flux size.To the requirement of this flow control valve for can regulate any opening degree flow, having stable behavior, again because the refrigerant loop of each indoor set all needs install, so also need this flow control valve to meet miniaturization, jumbo requirement.

For realizing above-mentioned requirements, now propose a kind of direct-driven motor-operated valve, screw mandrel and the rotor of this direct-driven motor-operated valve are fixed, and rotor is relative with the axial position of valve seat fixing, and screw mandrel is by screw-thread fit attaching nut, and nut is connected with spool.During work, electrical power, drive screw mandrel to rotate, the rotation of screw mandrel is converted into straight line motion by the nut coordinated with wire rod thread, and band movable valve plug moves axially to open or close port along the valve pocket of valve seat.

The valve seat of this direct-driven motor-operated valve has the valve port that first interface and the second interface are interconnected, valve seat core is installed with in this valve seat, the perisporium of valve seat core offers Flow-rate adjustment groove, during spool complete shut-down, namely time with valve port gluing, sealing, can shutoff Flow-rate adjustment groove, thus the refrigerant circulation cut off between valve seat first interface and the second interface, spool moves, after opening valve port, open Flow-rate adjustment groove gradually, first interface, by Flow-rate adjustment groove, valve port and the second orifice, regulates the cold medium flux between first interface and the second interface by Flow-rate adjustment groove.

Above-mentioned direct-driven motor-operated valve, compared with pilot-operated-type electric valve, can not only regulate cold medium flux, and can realize two-way circulating; Compared with common direct-driven motor-operated valve, eliminate gear train, decrease unnecessary transmission, decrease power loss, thus can motor size be reduced, meet valve body miniaturization, jumbo requirement.

After this direct-driven motor-operated valve power-off, the intrinsic location torque of motor is passed to nut and spool by screw mandrel, valve element position is kept with this, guarantee that valve port does not leak, but in real work, because the reasons such as vibration can cause the motion thread slippage of screw mandrel and nut, the axial locking power causing motor to pass to nut and spool by screw mandrel lost efficacy, thus cannot effectively guarantee that valve element position is constant, valve element position changes, and inevitably causes coolant leakage.

In view of this, after how guaranteeing motor power-off, valve element position is constant, avoids valve port to leak, and is the current technical issues that need to address of those skilled in the art.

Summary of the invention

The object of this invention is to provide a kind of direct-driven motor-operated valve, after can ensureing motor power-off, valve element position is constant, makes spool be in the position abutted against with valve port all the time, effectively avoids valve port to leak.

For solving the problems of the technologies described above, the invention provides a kind of direct-driven motor-operated valve, comprising the valve seat with valve pocket, be located at motor and the screw mandrel of described valve seat upper end; The rotor of described motor is relative with the axial position of described valve seat fixing, the upper end of described screw mandrel is fixedly connected with described rotor, described screw mandrel is connected with nut by screw-thread fit, described nut is connected with spool, and described spool can move axially to open or close the valve port being located at described valve seat under the drive of described nut; Be provided with spring between described nut and described spool, described spool is in full off state, described spool under the effect of described spring with described valve port gluing, sealing, lower end and the described spool of described nut are fitted.

As above design, when causing the motion thread slippage of screw mandrel and nut because of vibration or other reasons, when causing motor to be passed to the axial locking power inefficacy of nut and spool by screw mandrel, owing to being provided with spring between nut and spool, by the elastic force of spring, spool can be pressed in valve port, prevent from revealing.

Preferably, the coupling mechanism force that the location torque that the elastic force of described spring is less than described motor produces.

Preferably, the elastic force scope of described spring is 5N ~ 50N.

Preferably, the scope of the lead angle of the motion thread of described screw mandrel and described nut screw connection is 3 ° ~ 9 °, and described lead angle is greater than the equivalent friction angle of described motion thread.

Preferably, the scope of the pitch of described motion thread is 0.5mm ~ 1.5mm.

Preferably, the scope of the central diameter of described motion thread is 2.6mm ~ 5mm.

Preferably, the angle of thread of described motion thread is less than 60 °.

Preferably, described nut comprises the minor diameter part and large-diameter portion that coordinate with described wire rod thread;

The upper end of described spool has the receiving cavity holding described nut large-diameter portion, the inwall upper end of described receiving cavity offers the ring-shaped step of step surface towards described rotor, it is arranged nut cover plate, to limit described nut and described spool relative position in the axial direction.

Preferably, described nut and described spool have axial clearance, and spool is in non-full off state, and described nut and described nut cover plate abut against, and spool is in full off state, and the lower end of described nut and described receiving cavity abuts against.

Preferably, the scope of described axial clearance is 0.1mm ~ 0.4mm.

Preferably, the external diameter of described rotor and the diameter ratio of described valve port are 0.6 ~ 1.8.

Accompanying drawing explanation

Fig. 1 is the generalized section of direct-driven motor-operated valve provided by the present invention, shows the structure that valve port is in open mode;

Fig. 2 is the generalized section of direct-driven motor-operated valve provided by the present invention, shows the structure that valve port is in full off state;

Fig. 3 is the generalized section of the upper valve base assembly of direct-driven motor-operated valve in Fig. 1;

Fig. 4 is the generalized section of the mangetic core assembly of direct-driven motor-operated valve in Fig. 1;

Fig. 5 is the structural representation of the motion thread of screw mandrel and nut in Fig. 1.

In Fig. 1-5:

Motor 10, coil component 11, rotor 12, shell 20;

Valve seat 30, valve port 30a, upper valve base 31, path chamber 31a, large chamber, footpath 31b, step end face 31e, bearing 311, screw mandrel 312, wire rod thread section 312a, lower valve base 32, valve seat core 321, first adapter 322, second adapter 323;

Nut 41, minor diameter part 41a, large-diameter portion 41b, nut thread section 41c, nut cover plate 411, spool 42, spring 43.

Embodiment

Core of the present invention is to provide a kind of direct-driven motor-operated valve, and after can ensureing motor power-off, valve element position is constant, makes spool be in the position abutted against with valve port all the time, effectively avoids valve port to leak.

In order to make those skilled in the art person understand the present invention program better, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.

Here it should be noted that, the involved upper and lower noun of locality that waits is arranged in figure with component in Fig. 1 to Fig. 4 and component position each other defines herein, clear and convenient just in order to expression technology scheme.Should be appreciated that the noun of locality adopted should not limit the scope of the application's request protection herein.

Please refer to Fig. 1-2, Fig. 1 is the generalized section of direct-driven motor-operated valve provided by the present invention, shows the structure that valve port is in open mode; Fig. 2 is the generalized section of direct-driven motor-operated valve provided by the present invention, shows the structure that valve port is in full off state.

In this embodiment, direct-driven motor-operated valve comprises motor 10, valve seat 30 and screw mandrel 312; Wherein, valve seat 30 comprises the upper valve base 31 and lower valve base 32 that are fixedly connected with, both inner space, and the rotor 12 of motor 10 is coated at the upper end of upper valve base 31, and rotor 12 is relative with the axial position of upper valve base 31 fixing; Screw mandrel 312 is fixedly connected with rotor 12 through upper valve base 31, screw mandrel 312 is connected with nut 41 by screw-thread fit, nut 41 is connected with spool 42, and spool 42 can move axially to open or close the valve port 30a being located at lower valve base 32 along the inner chamber of valve seat 30 under the drive of nut 41; Be provided with spring 43 between nut 41 and spool 42, spool 42 is in full off state, spool 42 under the effect of spring 43 with valve port 30a gluing, sealing, lower end and the spool 42 of nut 41 are fitted.

Due to nut 41 and limit between its bounding means of rotating of circumference and there is fit up gap, when making spool 42 complete shut-down, still can be axially movable, thus disengaging valve port, because vibration or other reasons make spool 42 can not fit tightly all the time with valve port 30a, as above after design, when spool 42 departs from valve port 30a because of vibration or other reasons, by the elastic force of spring 43, spool 42 can be pressed in valve port 30a, prevent from revealing.

In concrete scheme, the elastic force of spring 43 is less than the coupling mechanism force of the location torque generation of motor 10.Wherein, the elastic force of spring 43 arranges and ranges preferably from 5N ~ 50N, if the elastic force of spring 43 is too small, then cannot play the effect of pressed spool 42, if the elastic force of spring 43 is excessive, then need the location torque of corresponding increase motor 10, so, add the size of motor 10, be unfavorable for valve body miniaturization.

It should be noted that, motor 10 has location torque, and the rotor 12 of obvious motor 10 is permanent magnet rotor.When actual setting, rotor 12 can select high performance magnetic material to make, to increase the location torque of motor 10.

In order to make motor 10 have certain location torque, the ratio of the diameter Dc of rotor 12 and the diameter Ds of valve port 30a range preferably from 0.6 ~ 1.8.

And the elastic force of this spring 43 is less than the coupling mechanism force of the location torque generation of motor 10, avoids the increase of motor 10 size.

Please composition graphs 3, Fig. 3 is the generalized section of the upper valve base assembly of direct-driven motor-operated valve in Fig. 1 in the lump.

Upper valve base assembly comprises upper valve base 31, screw mandrel 312, bearing 311 and rotor 12.As shown in the figure, upper valve base 31 comprises the path section and large footpath section of inserting rotor 12 inside, the inner chamber of upper valve base 31 is divided into epicoele and cavity of resorption by annular slab, this annular slab can be set to one with upper valve base 31, bearing 311 is provided with in described epicoele, the inner ring of this bearing 311 and the periphery wall of screw mandrel 312 are fitted, the inwall of outer ring and described epicoele is fitted, so, screw mandrel 312 is relative with the axial position of upper valve base 31 fixing by bearing 311, thus it is relative fixing with the axial position of upper valve base 31 with the rotor 12 that screw mandrel 312 is fixedly connected with, namely the structure of upper valve base 31 determines bearing 311, the relative position of screw mandrel 312 and rotor 12 three.

In order to make motor 10 can produce larger coupling mechanism force, the longitudinal center line of bearing 311, rotor 12 and coil component 11 overlaps, and can reduce the beating degree of rotor 12, reduces assemblage gap.

Wire rod thread section 312a is positioned at the cavity of resorption of upper valve base 31, and described cavity of resorption comprises path chamber 31a and large footpath chamber 31b, and path chamber 31a is used for leading to the nut 41 be threaded with screw mandrel 312, and large footpath chamber 31b coordinates with the inner chamber of lower valve base 32 and forms valve pocket; That is, the cavity of resorption of upper valve base 31 provides the space that mangetic core assembly that nut 41 and spool 42 form moves axially, and the vibrational power flow of upper valve base 31 makes the axial dimension of valve body reduce, and is conducive to valve body Miniaturization Design.

It is the generalized section of the mangetic core assembly of direct-driven motor-operated valve in Fig. 1 please also refer to Fig. 4, Fig. 4.

Mangetic core assembly comprises nut 41 and spool 42; Wherein, nut 41 comprises and has with the minor diameter part 41a of screw mandrel 312 screw-thread fit and large-diameter portion 41b, minor diameter part 41a the nut thread section 41c coordinated with wire rod thread section 312a, and two thread sections coordinate and form motion threads.The upper end of spool 42 has the receiving cavity holding large-diameter portion 41b, and the inwall upper end of described receiving cavity offers the ring-shaped step of step surface towards rotor 12, is provided with nut cover plate 411, to limit nut 41 and spool 42 relative position in the axial direction.

When rotor 12 rotates, drive screw mandrel 312 to rotate, and when driving nut 41 to move up, because the end of nut 41 large-diameter portion 41b and nut cover plate 411 interfere, thus movable valve plug 42 can be with to move up together, avoid nut 41 to depart from spool 42.

When rotor 12 rotates, drive screw mandrel 312 to rotate, and when driving nut 41 to move down, nut 41 directly can promote spool 42 and move down together, until close port 30 _a.

It is pointed out that the rotor 12 of motor 10 can rotate clockwise or rotate counterclockwise under the driving of coil component 11, thus can drive and nut 41 moves or moves down; When actual setting, when can be set as that rotor 12 rotates clockwise, drive on nut 41 and move, when rotor 12 rotates counterclockwise, drive nut 41 to move down; When can certainly be set as that rotor 12 rotates clockwise, drive nut 41 to move down, when rotor 12 rotates counterclockwise, drive on nut 41 and move.

The minor diameter part 41a of nut 41 stretches into the path chamber 31a of upper valve base 31 cavity of resorption, under the drive of screw mandrel 312, the minor diameter part 41a of nut 41 moves axially along described path chamber 31a, this path chamber 31a plays leading role to moving axially of nut 41, there is deflection when avoiding nut 41 to move axially, affect the sealability of spool 42 couples of valve port 30a.

Obviously, moving axially for guaranteeing that the rotation of screw mandrel 312 can be converted into by nut 41, to be with movable valve plug 42 to move axially, being also provided with bounding means, rotate with the circumference limiting nut 41.

The form that specifically arranges of bounding means can have multiple, wherein a kind of comparatively easy mode is be set to non-circular by the cross section of the path chamber 31a of upper valve base 31, as square etc., correspondingly, the path section 41a of nut 41 is set to the suitable column structure of the cross section of cross section and path chamber 31a.

In addition, the path chamber 31a of upper valve base 31 cavity of resorption of this direct-driven motor-operated valve and chamber, large footpath 31b connectivity part are formed towards the step end face 31e of valve port 30a, what the distance between this step end face 31e and valve port 30a defined spool 42 moves axially distance, understand with reference to figure 1, when spool 42 is in full-gear, first adapter 322 is communicated with the second adapter 323, and now, the upper-end surface of spool 42 abuts with step end face 31e; Understand with reference to figure 2, when spool 42 is in full-shut position, the seal ring of spool 42 lower end and valve port 30a fit to be formed and seal, and valve port 30a is closed, and the first adapter 322 is not communicated with the second adapter 323, and refrigerant circulation is completely cut-off.

This direct-driven motor-operated valve can realize two-way circulating, and the arrow in Fig. 1 and Fig. 2 indicates the flow direction of refrigerant; Wherein, solid arrow shows that refrigerant flows into from the first adapter 322, and the second adapter 323 is flowed out, and dotted arrow shows that refrigerant flows into from the second adapter 323, and the first adapter 322 is flowed out.

Further can optimize above-mentioned direct-driven motor-operated valve.

The driving torque of motor 10 is converted into axial lifting force through screw mandrel 312 and the motion thread of nut 41, and its relation is as shown in following formula (1):

$F=\frac{T\·2\mathrm{\π}\·\mathrm{\η}}{P}$ Formula (1)

Wherein, F---axial lifting force:

The driving torque of T---motor;

The pitch of P---motion thread;

The transmission efficiency of η---motion thread.

Therefrom known, the transmission efficiency η of the motion thread that screw mandrel 312 coordinates with nut 41 is the key that the driving torque affecting motor 10 is converted into axial lifting force.

Wherein, the transmission efficiency η of motion thread is as shown in following formula (2):

$\mathrm{\η}=\frac{\tan \mathrm{\φ}}{\tan (\mathrm{\φ}+{\mathrm{\ρ}}_v)}$ Formula (2)

The lead angle of φ---motion thread;

ρ _v---the equivalent friction angle of motion thread.

In formula (2): $\tan \mathrm{\φ}=\frac{\mathrm{nP}}{{\mathrm{\πd}}_2};$ ${\mathrm{\ρ}}_v=\mathrm{arctg}\left[\frac{\mathrm{\μ}}{\cos (\mathrm{\α}/2)}\right];$

Wherein, n represents the number of leads of motion thread, d ₂represent the central diameter of motion thread, α represents the angle of thread of motion thread, and μ represents friction factor.

Consider from the angle of driving moment conversion performance, need the lead angle φ of motion thread less, close from spool 42, the performance perspective that valve port 30a does not leak is considered, also needs the lead angle φ of motion thread less.

Simultaneously, upper stop due to this direct-driven motor-operated valve relies on spool 42 upper end to abut with the step end face 31e of upper valve base 31, lower stop relies on seal ring and the valve port 30a gluing, sealing of spool 42 lower end, during upper and lower stop, nut 41 is engaged with the motion thread of screw mandrel 312, during for avoiding spool 42 complete shut-down or standard-sized sheet, occur that, because motion thread kills the phenomenon of not opening, the lead angle φ of motion thread also needs the equivalent friction angle ρ being greater than motion thread _v, avoid occurring motion thread locking phenomenon.

If φ is too small for motion thread lift angle, there will be motion thread and kill phenomenon, if the lead angle φ of motion thread is excessive, when then spool 42 is in full off state, valve port 30a leaking performance can not be guaranteed, consider, the lead angle φ of the motion thread that screw mandrel 312 coordinates with nut 41 ranges preferably from 3 ° to 9 °.

Control for improving motor 10 precision that spool 42 moves axially position, the pitch P of the motion thread that screw mandrel 312 coordinates with nut 41 can less than normally be arranged, and it ranges preferably from 0.5mm to 1.5mm; For reducing the surface friction drag of motion thread, angle of thread α also can less than normally be arranged, and is generally less than 60 °, is preferably about 40 °; For ensureing the intensity of screw mandrel 312, avoid resisting moment excessive, the central diameter d of motion thread simultaneously ₂be preferably designed for 2.6mm to 5mm.

Can show the structural representation of the motion thread of screw mandrel and nut screw connection with reference to figure 5, Fig. 5, wherein, P represents nut, and d2 represents central diameter, and α represents angle of thread.

In a kind of concrete mode of execution, the central diameter d of motion thread ₂be chosen as 3.1mm, pitch P is 1.25mm, and angle of thread α is 40 °, and lead angle φ is 7.3 °.

The above-mentioned parameter to the motion thread that screw mandrel 312 coordinates with nut 41 is optimized, and can improve the transmission efficiency η of motion thread, and prevents nut thread section 41c to lose efficacy with being engaged of wire rod thread section 312a.

For reducing surface friction drag further, can be designed to arc-shaped at the bottom of the crest of wire rod thread section 312a screw thread and tooth, as shown in Figure 5, the radius R of arc-shaped can set needed for reality.Particularly, rolled thread can be adopted to process extrusion process be shaped.

For reducing equivalent friction angle, nut 41 can select PPS plastic production to form.

Further, have axial clearance L between nut 41 and spool 42, spool 42 is in non-full off state, nut 41 and nut cover plate 411 offset, now, axial clearance L is formed between the lower end surface of the receiving cavity of nut 41 lower end surface and spool 42, as shown in fig. 1; Spool 42 is in full off state, and nut 41 abuts against with the lower end of the receiving cavity of spool 42, and now, axial clearance L is formed between the upper-end surface of nut cover plate 411 and nut 41 large-diameter portion 41b.

Spool 42 is in full off state, and the receiving cavity lower end of nut 41 lower end surface and spool 42 directly offsets, and now, spring 43 is inoperative, relies on the coupling mechanism force pressed spool 42 transmitted by motion thread of motor 10; When motor 10 is energized, drive screw mandrel 312 to rotate, drive when nut 41 moves, nut 41 moves up stroke when being axial clearance L, offsets, be now just with movable valve plug 42 to be lifted away from valve port 30a with nut cover plate 411.The setting of axial clearance L, can guarantee to be in full off state when spool 42, motion thread generation slippage between nut 41 and screw mandrel 312, when nut 41 lower end surface is lifted away from the receiving cavity lower end surface of spool 42, movable valve plug 42 can not be with immediately to be lifted away from valve port 30a, and spool 42 still keeps fit-state with valve port 30a, now under the effect of spring 43 elastic force, spool 42 can be pressed in valve port 30a, avoids the generation of leaking.

Wherein, described axial clearance L range preferably from 0.1mm to 0.4mm.Certainly, needed for reality, also other values can be set as.

Above direct-driven motor-operated valve provided by the present invention is described in detail.Apply specific case herein to set forth principle of the present invention and mode of execution, the explanation of above embodiment just understands method of the present invention and core concept thereof for helping.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also carry out some improvement and modification to the present invention, these improve and modify and also fall in the protection domain of the claims in the present invention.

Claims (11)

1. a direct-driven motor-operated valve, comprises the valve seat (30) with valve pocket, is located at motor (10) and the screw mandrel (312) of described valve seat (30) upper end; The rotor (12) of described motor (10) is relative fixing with the axial position of described valve seat (30), the upper end of described screw mandrel (312) is fixedly connected with described rotor (12), described screw mandrel (312) is connected with nut (41) by screw-thread fit, described nut (41) is connected with spool (42), and described spool (42) can move axially to open or close the valve port (30a) being located at described valve seat (30) under the drive of described nut (41); It is characterized in that, spring (43) is provided with between described nut (41) and described spool (42), described spool (42) is in full off state, described spool (42) under the effect of described spring (43) with described valve port (30a) gluing, sealing, lower end and the described spool (42) of described nut (41) are fitted.

2. direct-driven motor-operated valve as claimed in claim 1, the elastic force of described spring (43) is less than the coupling mechanism force of the location torque generation of described motor (10).

3. direct-driven motor-operated valve as claimed in claim 2, it is characterized in that, the elastic force scope of described spring (43) is 5N ~ 50N.

4. direct-driven motor-operated valve as claimed in claim 1, it is characterized in that, the scope of the lead angle of the motion thread that described screw mandrel (312) coordinates with described nut (42) is 3 ° ~ 9 °, and described lead angle is greater than the equivalent friction angle of described motion thread.

5. direct-driven motor-operated valve as claimed in claim 4, it is characterized in that, the scope of the pitch of described motion thread is 0.5mm ~ 1.5mm.

6. direct-driven motor-operated valve as claimed in claim 5, it is characterized in that, the scope of the central diameter of described motion thread is 2.6mm ~ 5mm.

7. direct-driven motor-operated valve as claimed in claim 6, it is characterized in that, the angle of thread of described motion thread is less than 60 °.

8. the direct-driven motor-operated valve as described in any one of claim 1 to 7, is characterized in that, described nut (41) comprises and the minor diameter part (41a) of described screw mandrel (312) screw-thread fit and large-diameter portion (41b);

The upper end of described spool (42) has the receiving cavity holding described nut large-diameter portion (41b), the inwall upper end of described receiving cavity offers the ring-shaped step of step surface towards described rotor (12), it is arranged nut cover plate (411), to limit described nut (41) and described spool (42) relative position in the axial direction.

9. direct-driven motor-operated valve as claimed in claim 8, it is characterized in that, described nut (41) and described spool (42) have axial clearance, spool (42) is in non-full off state, described nut (41) and described nut cover plate (411) abut against, spool (42) is in full off state, and described nut (41) abuts against with the lower end of described receiving cavity.

10. direct-driven motor-operated valve as claimed in claim 9, it is characterized in that, the scope of described axial clearance is 0.1mm ~ 0.4mm.

11. direct-driven motor-operated valves as described in any one of claim 1 to 7, it is characterized in that, the external diameter of described rotor (12) and the diameter ratio of described valve port (30a) are 0.6 ~ 1.8.