JPS6199782A - Motor operated valve - Google Patents

Abstract

PURPOSE:To reliably restart a valve shaft in opposite direction after stopping the straight advance of the valve shaft by separately disposing a screw for moving the valve shaft forward and backward and a screw for stopping the forward and backward movement of the valve shaft in a motor operated valve. CONSTITUTION:A stopper bolt 17 having screw efficiency of 50% or more is fixed to the inner surface of the center of a cover 13, and stopper nut 18 having two through holes 18a disposed symmetrically about the central female screw is screwed in the bolt. A contact plate 22 is fixed to the forward end of the bolt. On the other hand, two pins 21 fixed to the back of the central concave portion of a rotary sleeve 20 are inserted in two through holes 18a of the stopper nut 18. As the screw efficiency of a stop screw 19 exceeds 50%, the pressure produced when the stopper nut 18 contacts the contact plate 22 acts in direction of loosening the screw.

Description

[Detailed Description of the Invention] [Industrial Application Field] It is used as an electronically controlled expansion valve used in the refrigeration cycle of room air conditioners, car air conditioners, etc., or as a proportional control valve used in combination with a microcomputer in the general industrial field. The present invention relates to electric valves.

[Constitution of conventional technology]

In order to provide a particularly simple and inexpensive motor-operated valve that combines a stepping motor and a valve and is controlled by a microcomputer, a motor-operated valve having a structure as shown in FIG. 4 has been put into practical use.

Its construction and operation will be explained in detail with reference to FIG.

The valve stem ■ is formed by integrating the needle valve ■ from the tip, the male screw ■, and the rotor of the motor consisting of a cylindrical permanent magnet with multi-pole magnetization on the outer periphery in this order, and the male screw ■ is.

It is fixed to the valve body ■ and is fitted with a propulsion bearing ■ that has a female thread [7] cut in the center. The outer periphery of the motor rotor ■ is covered with a thin cylindrical case ■, and the stator coil [phase] of the eK motor is fixed to the outside of this case [9] at a position corresponding to the motor rotor ■. ing.

The case [9] is airtightly integrated with the valve body ■ having a fluid inlet and outlet ■■ and a valve seat ■ by plasma welding, and the other end of the case [9] is also hermetically sealed with the lid 0.

■ is a relatively strong coil spring, and the male thread of the valve stem ■
It is compressively fitted between the large diameter part [stock] of the rear valve stem ■ and the propulsion bearing ■, and the [phase] is also a strong coil spring, and the stepped part at the rearmost end of the valve stem ■ is fitted OK. Fixed, valve stem ■! When moving to the 0 side, it hits the inner surface of M◎,
Km is configured so that it can be compressed. Male screw ■ and female screw ■
The propulsion screw 0 is configured with, for example, a double thread screw so that high efficiency can be obtained in a range of less than 5096 thread efficiency.

[Operation of conventional product] In the conventional product configured as described above, when a predetermined amount of current is applied to the stator coil @lK of the motor, the rotor 〇 rotates, and the valve shaft rotates due to the screw action of the male screw ■ and female screw ■. ■ moves forward (valve closing direction) or backward (valve opening direction) while rotating to a preset valve axis position f! ! (This much r
IFi, for example, in the valve closing direction, the needle valve ■ is the valve seat ■
In order to avoid the situation where the valve closes completely when seated on the needle valve ■■, a strong frictional force is generated between the threaded parts and the primary valve opening movement becomes impossible, the needle valve ■■ and the valve seat 0 must be placed very close together. (set so that there is a slight gap), the coil spring (2) contacts the 0 side of the propulsion bearing, or the coil spring [phase] and the inner surface of the lid 0 come into contact and the linear movement of the valve stem (2) is stopped. Coil spring■
The coil spring 2 acts to stop the movement in the valve-closing direction, and the coil spring 3 acts to stop the movement in the valve-opening direction.

[Problem that the invention seeks to solve]

The conventional motor-operated valve configured as described above has a small number of parts because the valve shaft [1] and the rotor [1] are integrated, and the structure directly stops linear motion.

Moreover, it is extremely inexpensive (i.e.,
Although it has the advantage of being able to be manufactured using iK, it has the disadvantage of being difficult to heat.

(1) In order to make it advantageous to start the valve stem in the reverse direction after stopping straight movement, the propulsion screw has the highest screw efficiency (
Ideally, a self-loosening screw with a thread efficiency of 5096 or higher should be used, but if the thread efficiency is set to 50% or higher, the stator coil (when φ is de-energized, fluid flows and the flow occurs on the valve stem) The rotor rotates due to physical force and becomes uncontrollable.Therefore, the screw efficiency must be less than 5096.

Reverse rotation after the valve stem (■) is stopped straight is disadvantageous.

(2) In order to make it advantageous to start the valve stem in the reverse direction after being stopped in a straight line, it is necessary to make the thread efficiency as high as possible, even if it is less than 60%, Since measures are taken to increase the size of the valve, the propulsive force of the valve stem (2) generated by the screw action is reduced.

Therefore, in order to overcome the load (fluid force) K applied to the valve stem (2) and operate the valve, it is necessary to take measures such as increasing the size of the motor and increasing the input current.

[Means for solving problems]

The purpose of the present invention is to overcome the above-mentioned drawbacks of conventional products.

This is an attempt to solve this problem while taking advantage of the features of conventional products (the valve stem [1] and rotor ■ are integrated, making the configuration simple and requiring no complicated parts or precise adjustments for straight-line locking). .

The idea behind this method is to move the valve stem ■ back and forth, or use the first screw (thread value - φ is small and the screw with the smallest diameter possible to achieve high propulsive force), and to stop the valve stem ■ from moving back and forth. Screws (screws that loosen naturally with screw efficiency of 50%)
(They are installed separately in the valve train so that each function can work independently.

〔Example〕

The structure of the present invention will be explained with reference to FIGS. 1 to 8.

Items with the same numbers in Figures 1 and 2 are designated by the same numbers.

This is a part that functions in the same way as conventional products.

The basic configuration of the present invention is the same as that of the conventional product.

Fix a stopper gelt 0 with a screw efficiency of 50% or more to the center inner surface of the go, and attach it to this stopper bolt 0.

A stopper nut 3 having two through holes (13a) provided at symmetrical positions across the central female thread is screwed in, and a backing plate is fixed to the tip of the stopper nut 3. Two bottles fixed to [phase]
the two through holes (181L) of the stopper nut.
K was inserted.

In addition, the above-mentioned backing plate [phase] is attached to the valve seat ■ when the valve stem ■ moves forward.
◇ Also, the propulsion screw [phase] with male screw ■ and female screw ■ has a thread efficiency of 6.
It should be less than 0g6 and as small in diameter as possible.

The screw lead is configured to be small, and the winding direction of the propulsion screw [phase] and the stop screw [phase] may be either right or left.

In the explanation of "action" below, lead lI of the propulsion screw [phase] < lead of the stop screw [phase]! , and the same direction screws will be explained.

[For production]

Similar to the conventional product, when the stator coil [phase] is energized to rotate a certain amount in the closing direction, the motor rotor ■ and the valve shaft ■ rotate integrally (rotate, and the valve rotates per rotation due to the action of the propulsion screw). The shaft ■ advances by 11 minutes with Lee.On the other hand, the stopper nut [phase] fitted with the stopper bolt @ fixed to IFQΦ is rotated by the bottle [phase] that rotates together with the rotor 〇, so the stopper When Natsu accepts the move, the beam moves forward by an inch.

The electric valve is adjusted in advance so that when the valve stem ■ rotates a predetermined amount in the valve closing direction, the stopper nut [phase] hits the backing plate [phase] just before the needle valve ■ seats on the valve seat and completely closes the valve. Because of this, the valve stem rotates and (aXl
t,) The point at which the branch shaft moves forward (the point at which the stopper nut [phase] moves over the stopper bolt by (aXlt))
At this point, the stopper nut 1 hits the backing plate [phase] and the stopper nut [phase] is stopped from moving in a straight line. Therefore, the rotational and linear movement of the valve stem (2) is also stopped. This cause is shown in FIG. The tightening force of the screw acts only on one part of the stopper nut, but the thread efficiency of the stopper screw [phase] exceeds 60%, so the stronger the screw is screwed in, the more the stopper nut [phase] is applied. The reaction force when it hits the plate [phase] acts as a force in the direction of loosening the screw, so it does not interfere with the primary movement in the opening direction.

Subsequently, when the stator coil [phase] is energized in the valve opening direction, the stopper nut [phase] immediately leaves the contact plate [phase] surface, and the valve stem rotates backward and moves straight to close the stopper nut. [phase] slides backwards (along bin 0);
Eventually, as shown in Fig. 11E2, it hits the inner surface of the lid 0, and the stopper nut [phase] stops moving straight and the rotational straight movement of the valve stem 1 stops, just like when the valve is closed and stopped.

In the above action, the rotational force of the valve stem (■) is:

The propulsion screw [phase] part converts it into propulsive force, which overcomes the fluid force and moves the valve stem■ back and forth.However, the propulsion screw has a small diameter with screw efficiency < SO*, and the screw lead is small. Since it has a small structure, it is possible to obtain a large propulsive force even with the output torque of the same motor.

Let's explain this from the theoretical perspective of screws.

De Effective diameter of i thread (1) ρ Equivalent friction angle of thread surface (″) ρ;-(μ)μ
;Friction coefficient β of the thread surface ;Lead angle of the screw (β””-1(M)l;
If the lead T of the screw is the output torque of the motor (g・α) F and the driving force of the response shaft (f), then from the formula F = T/〒・−(ρ+β), if the output is the same, the effective diameter of the screw De The smaller the lead l of the screw, the larger the propulsive force.

〔Effect of the invention〕

As explained above, the screw that had the functions of both propulsion and straight-line stopping in conventional products has been divided into a screw part only for propulsion and a threaded part only for straight-line stopping.
A separate AK is provided in the motor-operated valve (the screw shape can be selected to better suit each function, and as a result (1) it is possible to reliably restart the valve stem in the opposite direction after it has been stopped from moving straight.

(2) The propulsive force of the valve stem (■) can be increased, making it possible to downsize the motor and reduce input current.

This is an industrially useful invention that has the following effects.

Brief description of the surface Figure 1 is a longitudinal sectional view showing a closed valve-shaped face in one embodiment of the present invention;
FIG. 2 is a longitudinal cross-sectional view showing a valve opening portion in the embodiment shown in FIG. 1, and FIG. 8 is a perspective view showing a stop screw portion.

Figure 4 is a vertical WFR view of the conventional product.

Claims (1)

[Claims] 1) By energizing the stator coil [10] of the motor fixed to the outer periphery of the case [9] made of a non-magnetic material, a motor with a small diameter and a small screw lead housed in the case [9] is A rotor [5] of a motor formed integrally with the valve shaft [1] having a thread [4] is rotated, and this rotation is transmitted to the valve shaft [1] by a propulsion bearing [8] having a female thread [7]. In the motor-operated valve that controls the opening degree of the valve seat [2] by converting it into a linear motion, a stopper bolt [17] with a thread efficiency of 50% or more is fixed to the center inner surface of the lid [13], A stopper nut [18] having two through holes (13a) located symmetrically across the center female thread is screwed into this stopper bolt [17], and a backing plate [22] is fixed to the tip of the stopper nut [18]. , while the rotor sleeve [2
0] is inserted into two through holes (18a) of the stopper nut.