JP2003130501A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve capable of reducing the number of parts to be more compact and reduce costs. SOLUTION: The expansion valve comprises a valve part and a power element that drives a valve element 23 of the valve part in response to the temperature and pressure of the refrigerant outputted from an evaporator, and is assembled by screwing them. A coil spring 30 that energizes the valve element 23 in the valve closing direction is placed in a nearer side to the power element than to the valve element 23, and the load of the coil spring 30 is varied by the amount of screwing a body 21 of the valve part in the power element to adjust a set value. Since the coil spring 30 is placed inside of the valve element 23 to shorten the full length, and the set value is adjusted by the screwing amount of the body 21 of the valve part to reduce the number of adjusting screws, the expansion valve of more compact and low cost can be constructed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve.
The present invention relates to an expansion valve that expands a high-pressure liquid refrigerant to a low-temperature low-pressure refrigerant, supplies the refrigerant to an evaporator, and controls the refrigerant flow rate so that the refrigerant at the evaporator outlet has a predetermined superheat degree.

[0002]

2. Description of the Related Art In an automobile air conditioner system, a high temperature and high pressure gas refrigerant compressed by a compressor is condensed by a radiator, and the condensed liquid refrigerant is adiabatically expanded by an expansion valve into a low temperature and low pressure refrigerant, which is converted into a low temperature and low pressure refrigerant. A refrigeration cycle is formed in which an evaporator is used to evaporate and return it to the compressor. The evaporator supplied with the low-temperature refrigerant exchanges heat with the air in the vehicle compartment to perform cooling.

The expansion valve senses changes in the temperature and pressure of the refrigerant on the outlet side of the evaporator and boosts / decreases the pressure inside the power element, and the flow rate of the refrigerant supplied to the inlet side of the evaporator based on the boosting / decreasing pressure inside the power element. And a valve section for controlling the.

In a block type expansion valve in which refrigerant at the evaporator outlet is passed through the inside of the main body so that the temperature and pressure of the refrigerant can be sensed inside, the valve portion is formed in a block type body which also serves as a pipe joint. There is. In this valve part,
A valve hole is formed in a wall provided so as to block the refrigerant passage in the middle of the refrigerant passage that communicates the refrigerant inlet that receives the high-pressure refrigerant and the refrigerant outlet that sends out the low-pressure refrigerant, and the side of the valve hole where the power element is located. A valve element is arranged on the opposite side to the valve seat around the valve hole so that the valve element can be moved toward and away from the valve seat. The displacement of the power element in the axial direction, which changes by detecting the temperature and the pressure, is transmitted through the shaft. The end of the coil spring opposite to the side receiving the valve body is received by an adjusting screw. The adjusting screw adjusts the set value at which the valve body starts to open by rotating the adjusting screw to adjust the load of the coil spring.

[0005]

However, the conventional block type expansion valve has a power element, a shaft,
Since the valve body, the coil spring, and the adjusting screw are arranged in this order on the same axis, the axial length inevitably needs to accommodate them, which makes it difficult to make them compact. It was

Further, since the valve portion of the expansion valve serves as both the body and the block of the joint, there is a problem that a body having a shape suitable for the application place such as piping, joints, or evaporator is required. .

The present invention has been made in view of the above points, and can reduce the number of parts, be more compact and reduce the cost, and can be similarly attached to different application places. The purpose is to provide an expansion valve.

[0008]

In order to solve the above problems, the present invention comprises a valve section for controlling the flow rate of a refrigerant and a power element for driving a valve element of the valve section according to the temperature and pressure of the refrigerant. In the expansion valve provided, there is provided an expansion valve, wherein spring means for urging the valve body in a valve closing direction is arranged closer to the power element than the valve body.

According to such an expansion valve, the total length can be shortened by arranging the spring means inside the valve body, and a compact and low-cost expansion valve can be constructed.

Further, according to the present invention, the connecting portion between the valve portion and the power element has a screw structure, and the load of the spring means is changed by the amount of screwing the body of the valve portion into the power element. I am trying to adjust. Since the set value is adjusted by the screwing amount of the valve body, the adjusting screw can be reduced, and the expansion valve can be made more compact and low cost.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings by taking a case of being mounted on a joint as an example.

FIG. 1 is a vertical sectional view showing an expansion valve according to a first embodiment. The expansion valve according to the first embodiment is composed of a power element and a valve portion. The power element has a configuration in which the diaphragm 11 is held between the upper housing 12 and the lower housing 13 and their outer peripheral edge portions are welded to each other, and a center disk 14 is arranged on the lower surface of the diaphragm 11. The center disk 14 has its outer peripheral edge portion bent downward in the drawing, and a plurality of communication holes 15 are formed in the bent portion. Refrigerant gas is enclosed in an upper sealed space surrounded by the diaphragm 11 and the upper housing 12. The inner peripheral edge portion of the lower housing 13 is bent upward in the drawing, and the inner wall surface thereof is threaded.

The valve portion has a body 21 formed by forming a pipe. At the central axis position of the body 21, a shaft 22 is arranged so as to be movable back and forth in the axial direction. The upper end of the shaft 22 is in contact with the lower surface of the center disk 14, and the ball-shaped valve element 23 is spotted on the lower end. A valve that is welded and cooperates with a valve seat 24 formed on the lower end surface of the body 21 to adiabatically expand the liquid refrigerant is formed.

A holder 25 for holding the upper portion of the shaft 22 is arranged on the upper portion of the body 21. The holder 25 holds the shaft 22 at the axial position by inserting the shaft 22 in the center and fitting legs extending in three directions from the center into the upper space of the body 21. Holder 25
Is provided with a coil spring 26 that applies a lateral load to the shaft 22, and has a vibration damping mechanism that suppresses abnormal noise by suppressing vibration of the shaft 22 in the axial direction.

The shaft 22 is also held by a drawn portion 27 drawn near the center of the body 21. An O-ring 28, a washer 29, and a coil spring 30 are arranged above the narrowed portion 27, and the upper end of the coil spring 30 is in contact with a stopper 31 fitted to the shaft 22. Therefore, the shaft 2
The coil spring 30 urges the valve 2 upward in the figure, that is, in the valve closing direction.

A screw is formed on the outer peripheral portion of the upper portion of the body 21, the upper end side of which constitutes a screwing portion with the lower housing 13, and the lower end side thereof is a joint 40 to which this expansion valve is mounted. Constitutes a screwing part of the. The joint 40 is derived from the evaporator 41 and a port 41 to which a pipe for introducing a high-pressure refrigerant is connected, a port 42 to which a pipe is introduced for introducing a low-temperature / low-pressure refrigerant that is adiabatically expanded by an expansion valve into an evaporator. Ports 43 and 44 to which pipes for passing the refrigerant are connected are provided.

Further, the body 21 of the valve portion opens from the refrigerant outlet hole 32 provided at the corresponding position of the passage communicating with the port 42 of the joint 40 and the passage communicating with the ports 43 and 44 and returns from the evaporator. And a coolant sensing hole 33 that allows the coolant to be introduced up to the diaphragm 11 of the power element.

In this expansion valve, the coil spring 30 for urging the valve body 23 in the valve closing direction is arranged not on the high pressure side but on the low pressure side between the valve body 23 and the power element. As a result, the total length of this expansion valve can be shortened. Further, this expansion valve is assembled by screwing the lower housing 13 of the power element onto the upper portion of the body 21, and the amount of screwing the body 21 into the lower housing 13 is adjusted to adjust the load of the coil spring 30. By doing so, the set value of this expansion valve is adjusted. After the adjustment, the screwed portion between the body 21 and the lower housing 13 is fixed by welding or application of a screw lock. As a result, the adjusting screw for adjusting the set value is not required, and the length of the expansion valve can be further shortened. The expansion valve thus assembled is inserted into the joint 40, and is screwed to the joint 40 by using the screw portion provided on the upper outer peripheral surface of the body 21.

In the expansion valve having the above construction, when a high-pressure refrigerant is introduced from the port 41 of the joint 40, the refrigerant flows between the valve seat 24 on the lower end surface of the body 21 and the ball-shaped valve body 23. The refrigerant, which has been adiabatically expanded by passing through the gap and has become low temperature and low pressure, is sent to the evaporator via the refrigerant outlet 32 of the body 21 and the port 42 of the joint 40, where it is heat-exchanged with the air in the vehicle interior to be cooled. The room air is cooled.

The refrigerant evaporated by heat exchange in the evaporator enters through the port 43 of the joint 40 and is sent through the port 44 to the compressor. The passage through which the refrigerant returned from the evaporator passes through the joint 40 is the refrigerant sensing hole 33 of the body 21, the holder 25, and the center disk 1.
Since it communicates with the room on the lower surface of the diaphragm 11 through the communication hole 15 of No. 4, the diaphragm 11 can detect the temperature and pressure of the refrigerant discharged from the evaporator. Since the diaphragm 11 is displaced in the axial direction according to the temperature and pressure of the refrigerant, the displacement is transmitted to the valve body 23 via the shaft 22 and adjusts the valve opening.

FIG. 2 is a vertical sectional view showing an expansion valve according to the second embodiment. In FIG. 2, the same or equivalent elements as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The expansion valve according to the second embodiment differs from the expansion valve according to the first embodiment in that the body 21 of the valve portion is formed by a cutting part. Further, in this expansion valve, the lower end portion of the body 21 is extended to such an extent that the valve body 23 is hidden, and therefore, the port 4 of the joint 40 is provided.
A coolant introduction hole 34 is provided at a position corresponding to the passage communicating with 1.

The structure of the screwed portion between the lower housing 13 of the power element and the body 21 of the valve portion, the abnormal noise countermeasure by the coil spring 26, the arrangement of the coil spring 30 at the passage position through which the refrigerant discharged from the evaporator passes, the valve Regarding the structure in which the O-ring 28 seals the pressure equalizing portion between the space on the downstream side of the body 23 and the space communicating with the power element,
It is the same as the expansion valve according to the embodiment.

In this example, the case where the body 21 of the valve portion is made of a cut part is shown, but it may be made of a resin molded product. FIG. 3 is a vertical sectional view showing an expansion valve according to a third embodiment. In FIG. 3, the same or equivalent elements as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the expansion valve according to the third embodiment,
The holder 25a has a function of only holding the upper portion of the shaft 22 at the axial position of the body 21, and does not have a mechanism that applies a lateral load to the shaft 22. Instead, the center disk 14a arranged on the lower surface of the diaphragm 11
At the portion contacting the shaft 22,
b is formed. As a result, the upper end surface of the shaft 22 is pressed against the tapered portion 14b by the biasing force of the coil spring 30, so that a lateral component force acts on the shaft 22 and a lateral load is applied to the shaft 22.

Further, in this expansion valve, the lower housing 1
The inner peripheral edge of 3 is bent downward in the figure, and the inner wall surface thereof is threaded. The threaded portion of the lower housing 13, together with the threaded portion provided on the outer peripheral portion of the upper portion of the body 21, constitutes a screwed portion for coupling the power element and the valve portion and adjusting the set value.

The arrangement of the coil spring 30 at the passage position through which the refrigerant discharged from the evaporator passes and the seal structure of the pressure equalizing portion by the O-ring 28 are the same as those of the expansion valve according to the first embodiment. .

FIG. 4 is a vertical sectional view showing an expansion valve according to a fourth embodiment. In FIG. 4, elements that are the same as or equivalent to the elements shown in FIG. 1 are assigned the same reference numerals and detailed explanations thereof are omitted.

In the expansion valve according to the fourth embodiment,
The function of holding and fixing the upper portion of the shaft 22 at the axial position of the body 21 and the function of suppressing vibration of the shaft 22 in the axial direction are realized by the leaf spring 26a. This leaf spring 2
6a is formed by integrally forming a ring-shaped base portion that is hooked on the shaft 22 and a plurality of leg portions that radially extend from the base portion, and the inner wall surface of the body 21 on the tip side of each leg portion. The sliding contact portion is embossed.

The arrangement of the coil spring 30 at the passage position through which the refrigerant discharged from the evaporator passes and the sealing structure of the pressure equalizing portion by the O-ring 28 are the same as those of the expansion valve according to the first embodiment. .

FIG. 5 is a vertical sectional view showing an expansion valve according to a fifth embodiment. 5, elements that are the same as or equivalent to the elements shown in FIG. 4 are assigned the same reference numerals and detailed explanations thereof are omitted.

In the expansion valve according to the fifth embodiment,
The configuration of the screwed portion between the lower housing 13 of the power element and the body 21 of the valve portion is different from that of the expansion valve according to the fourth embodiment. That is, in this expansion valve, the inner peripheral edge portion of the lower housing 13 extends straight, and the inner wall surface corresponding to the thickness thereof is threaded. The threaded portion of the lower housing 13, together with the threaded portion provided on the outer peripheral portion of the upper portion of the body 21, constitutes a screwed portion for coupling the power element and the valve portion and adjusting the set value.

Measures against abnormal noise by the leaf spring 26a, and the coil spring 3 to the passage position through which the refrigerant discharged from the evaporator passes
The arrangement of 0 and the sealing structure of the pressure equalizing portion by the O-ring 28 are the same as those of the expansion valve according to the fourth embodiment.

FIG. 6 is a vertical sectional view showing an expansion valve according to a sixth embodiment. In FIG. 6, the same or equivalent elements as those shown in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the expansion valve according to the sixth embodiment,
A coil spring 30 for urging the shaft 22 and the valve body 23 in the valve closing direction is arranged above a passage position through which the refrigerant discharged from the evaporator passes, and a seal of a pressure equalizing portion is provided by a packing 28.
It is done by a. The coil spring 30 includes a washer 29 holding the packing 28a and the shaft 2
It is arranged between the leaf spring 26a and the leaf spring 26a. As shown in the figure, the leaf spring 26a may be reinforced to prevent the leaf spring 26a from coming off by a stopper 31 that is hooked on the shaft 22.

Further, in this expansion valve, the throttle portion 27 of the body 21 is formed to be long in the axial direction, and the throttle portion 27 holds the shaft 22 so as to be movable back and forth in the axial direction. In this expansion valve, the coil spring 30 for urging the shaft 22 and the valve body 23 in the valve closing direction is arranged so as to partially overlap the leaf spring 26a for preventing abnormal noise in the axial direction. Therefore, the total length of the body 21 can be shortened, and the body 21 can be made compact.

The lower housing 13 of the power element has an inner peripheral edge portion bent downward in the figure, and an inner wall surface of which is threaded to form a threaded portion with the body 21 of the valve portion. The points are the same as those of the expansion valve according to the fourth embodiment.

FIG. 7 is a vertical sectional view showing an expansion valve according to a seventh embodiment, and FIG. 8 is an enlarged plan view showing a holder. In FIG. 7, the same or equivalent elements as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the expansion valve according to the seventh embodiment,
The disc spring 30a is used as a means for urging the shaft 22 and the valve body 23 in the valve closing direction. This disc spring 30a
Are arranged on the upper surface of a holder 25 for holding the shaft, which is arranged on the upper portion of the body 21. The holder 25 is shown in FIG.
As shown in FIG. 5, a leg portion 25b extending in three directions from the center is provided, and a shaft holding hole 25c for inserting the shaft 22 and holding the shaft 22 so as to advance and retract in the axial direction is formed at the center thereof. One of the legs 25b has a spring accommodating portion 25d in which a coil spring 26 that applies a lateral load to the shaft 22 is accommodated. The upper surface of the holder 25 has a disc spring 3
It is recessed so that 0a can be placed.

The upper surface of the disc spring 30a is stopped by an E-ring 35 fitted on the shaft 22. As a result, the shaft 22 is loaded by the disc spring 30a in the upward direction in the figure, and the valve body 23 is biased in the valve closing direction.

Further, the pressure equalizing portion is sealed by an O-ring 28 arranged above the throttle portion 27 of the body 21. The O-ring 28 is pressed by a washer 29 press-fitted into the body 21, and
Is moved in the axial direction so as not to be displaced from a predetermined position.

The configuration of the screwed portion between the lower housing 13 of the power element and the body 21 of the valve portion and the noise suppression by the coil spring 26 are the same as those of the expansion valve according to the first embodiment.

FIG. 9 is a vertical sectional view showing an expansion valve according to the eighth embodiment. In FIG. 9, elements that are the same as or equivalent to the constituent elements shown in FIG. 7 are assigned the same reference numerals and detailed explanations thereof are omitted.

In the expansion valve according to the eighth embodiment,
The sealing in the pressure equalizing portion is performed by the throttle portion 27 of the body 21. Therefore, the expansion valve according to the eighth embodiment differs from the expansion valve according to the seventh embodiment in that the O-ring 28 and the washer 29 are omitted.

The seal of the pressure equalizing portion is the throttle portion 2 of the body 21.
This is realized by making 7 longer in the axial direction and reducing the clearance with the shaft 22.

[0046]

As described above, according to the present invention, the coil spring for urging the valve body in the valve closing direction is arranged between the power element and the valve body. As a result, the total length of the expansion valve can be shortened by the length of the coil spring as compared with the case where the expansion valve is arranged outside in the axial direction of the valve body, and the expansion valve can be configured compactly and at low cost. .

Further, in the present invention, the power element and the body of the valve portion are screwed to each other, and the set value is adjusted by varying the load of the coil spring by the screwing amount of the body into the power element. Configured. As a result, the adjusting screw for varying the load of the coil spring can be reduced, and the expansion valve can be configured more compactly and at low cost.

Furthermore, since the present invention has a unit type consisting of a power element and a valve section, which are the basic functions of the expansion valve, it can be installed in different places such as inside a pipe, a joint, or an evaporator in the same manner, and it is versatile. It is possible to provide a rich expansion valve.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an expansion valve according to a first embodiment.

FIG. 2 is a vertical sectional view showing an expansion valve according to a second embodiment.

FIG. 3 is a vertical sectional view showing an expansion valve according to a third embodiment.

FIG. 4 is a vertical sectional view showing an expansion valve according to a fourth embodiment.

FIG. 5 is a vertical sectional view showing an expansion valve according to a fifth embodiment.

FIG. 6 is a vertical sectional view showing an expansion valve according to a sixth embodiment.

FIG. 7 is a vertical sectional view showing an expansion valve according to a seventh embodiment.

FIG. 8 is an enlarged plan view showing a holder.

FIG. 9 is a vertical sectional view showing an expansion valve according to an eighth embodiment.

[Explanation of symbols]

11 diaphragm 12 Upper housing 13 Lower housing 14 Center disc 14a Center disk 14b Tapered part 15 communication holes 21 body 22 shaft 23 valve body 24 valve seat 25,25a holder 25b leg 25c Shaft holding hole 25d spring housing 26 coil spring 26a leaf spring 27 Throttle 28 O-ring 28a packing 29 washers 30 coil spring 30a disc spring 31 Stopper 32 Refrigerant outlet 33 Refrigerant sensing hole 34 Refrigerant introduction hole 35 E-ring 40 joint 41, 42, 43, 44 ports

Claims (15)

[Claims] 1. An expansion valve comprising a valve section for controlling a flow rate of a refrigerant and a power element for driving a valve body of the valve section according to a temperature and a pressure of the refrigerant, wherein the valve body is attached in a valve closing direction. An expansion valve in which a biasing spring means is arranged closer to the power element than the valve body. 2. A set value is set by changing a load of the spring means by an amount by which the body of the valve portion is screwed into the power element so that a connecting portion between the valve portion and the power element has a screw structure. The expansion valve according to claim 1, wherein the expansion valve is adjusted. 3. The spring means has one end on the valve body side abutting against a portion of the valve portion that does not change relative to the body, and the other end on a shaft for transmitting the driving force of the power element to the valve body. The expansion valve according to claim 1, wherein the expansion valve is a coil spring arranged around the shaft so as to come into contact with a stopper that is hooked. 4. The expansion valve according to claim 1, further comprising a holding means for holding a shaft for transmitting the driving force to the valve element near the power element. 5. A dish arranged such that the spring means has an end portion on the valve body side abutting on the holding means and an end portion on the power element side abuts on a stopper hooked on the shaft. The expansion valve according to claim 4, wherein the expansion valve is a spring. 6. The expansion valve according to claim 1, further comprising damping means for suppressing vibration in the axial direction of the shaft that transmits the driving force of the power element to the valve body. 7. The vibration damping means is a coil spring which is housed in a holding means which holds a shaft for transmitting the driving force to the valve element near the power element and applies a lateral load to the shaft. 7. The method according to claim 6, wherein
Expansion valve described. 8. The vibration damping means holds and fixes a shaft for transmitting a driving force to the valve body near the power element, and has a plurality of leg portions whose tip portions are in sliding contact with the body of the valve portion. The expansion valve according to claim 6, wherein the expansion valve is a leaf spring. 9. The spring means has one end on the valve body side abutting against a portion of the valve portion that does not change relative to the body, and the other end on a portion holding and fixing the shaft of the leaf spring. 9. The expansion valve according to claim 8, wherein the expansion valve is a coil spring arranged around the shaft so as to abut. 10. The damping means has a structure in which a taper portion is formed in a part of a center disk which receives a diaphragm of the power element, and a tip of the shaft is brought into contact with the taper portion. The expansion valve according to claim 6, wherein 11. The expansion valve according to claim 1, wherein the body is formed by forming a pipe. 12. The expansion valve according to claim 1, wherein the body is formed of a machined product. 13. The expansion valve according to claim 1, wherein a pressure equalizing portion between a space on the downstream side of the valve body and a space communicating with the power element is sealed by an O-ring. 14. The expansion valve according to claim 1, wherein a pressure equalizing portion between a space on the downstream side of the valve body and a space communicating with the power element is sealed by packing. 15. The expansion valve according to claim 1, wherein a pressure equalizing portion between a space on the downstream side of the valve body and a space communicating with the power element is sealed by a throttle portion of the body.