JPH0253665B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a pressure piping line that selectively switches and supplies high pressure and low pressure to one pressure supply target device, for example, between a compressor and an air conditioner of a variable capacity type vehicle air conditioner. The present invention relates to a three-way valve installed in a vehicle, and particularly relates to an improved structure of a three-way valve having a solenoid-operated plunger.

Prior Art In a three-way valve that uses the excitation of a solenoid to pivot a plunger and open and close the valve port accordingly, spring force is used to return the plunger when the solenoid is deenergized and to press the valve element at the valve port. Therefore, if the spring force is strengthened to ensure the plunger return operation and to increase the valve closing pressure by the valve, excessive electric power is required to excite the solenoid, and the solenoid itself is small. If the spring strength is weakened in order to reduce the excitation power and reduce the excitation power, there is a problem in that movable members such as the plunger and valve element resonate within the three-way valve in response to external vibrations. To further explain this in detail with reference to the drawings, as shown in Fig. 1, in the conventional three-way valve having a solenoid-operated plunger, a core 7 is fitted and fixed in a hollow cylinder 6. A valve seat consisting of a nozzle 8 is provided at the inner end, and a hollow plunger 10 is loosely fitted into the cylinder 6. A spring 12 is inserted into the plunger 10, and flanges 10a are provided at both ends inside the plunger 10. 10b applies spring pressure to press the valve elements 11, 13, whose movement in the axial direction outward is restricted, against the respective flanges 10a, 10b. Flanges 1 and 2 are screwed or fitted to both ends of the cylinder 6, and another valve seat consisting of a nozzle 9 is inserted into the flange 2 on the side where the plunger 10 is loosely fitted, and is fitted around the cylinder. Spring pressure is applied by a spring 14 on the outer periphery of the plunger so that the valve element 13 provided on the end face of the plunger 10 is always pressed against the valve seat formed by the nozzle 9 when the solenoid 16 is not activated.
A first passage 3 is formed on the flange 1 side and communicates with the valve seat of the nozzle 8 through the through hole of the core 7.
Further, a second passage 4 is formed on the flange 2 side to communicate with the valve seat of the nozzle 9, and a third passage 5 is opened near the second passage 4. In such a three-way valve, the distance t between the plunger 10 and the core 7
is the dimension l ₁ from the end face of nozzle 9 to the end face of core 7,
Plunger dimension l ₂ , dimension a from the cylinder end face to the core end face, dimension b from the cylinder end face to the brim of the cylinder 6, from the flange end face to the nozzle 9
Assuming the dimension to the end face c, the plunger body length d, and the thickness e of the plunger flange 10b, t=l ₁ -l ₂ l ₁ = a-b + c l ₂ = d-e t=a-b+c-(d -e), and the maximum value of the distance t, that is, the stroke value of the plunger 10, is when the value of the addition and subtraction of the five standard dimensions a, b, c, d, and e, each with their own machining dimension tolerance, is the maximum value. , the capacity of the solenoid is 〓
Even when the distance t is maximum, it is necessary to have the ability to compress the springs 12 and 14 and bring the core 7 and the plunger 10 into sufficient contact, so the larger the distance t becomes due to the accumulation of dimensional tolerances, the larger the distance t becomes. capacity solenoid 16 is required, and the solenoid 16
This results in an increase in size and power consumption. Therefore, in order to reduce the capacity of the solenoid 16, the springs 12, 1
4 may be weakened, but if the springs 12 and 14 are weakened, the holding force of the plunger 10 and the valve elements 11 and 13 by the springs becomes unstable, and resonance is likely to occur when vibration is applied from the outside.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned conventional disadvantages by making it possible to set the stroke amount of a plunger to an appropriate narrow value without unnecessarily tightening the machining accuracy, and thereby increasing the spring strength. The purpose is to reduce the solenoid capacity without weakening it, reduce power consumption, and provide a three-way valve that is less likely to resonate even when vibrations are applied from the outside. In order to achieve this object, the present invention provides first and second passages that are held and fixed by a flange and communicate with the outside through the flange, at both ends in the axial direction, and near the second passage. a hollow cylinder having a third passage passing through the flange and communicating with the outside; and a hollow cylinder that is inserted and fixed to the first passage side of the hollow cylinder and has a valve port at its inner end. a first valve seat;
a cylindrical core having a through hole that communicates between the valve seat and the first passage; and a cylindrical core that is sandwiched between the flange and the hollow cylinder and faces the first valve seat of the cylindrical core in the axial direction. a valve seat forming member forming a second valve seat at an inner end of the second passage and forming a joint surface with the hollow cylinder and an end surface of the second valve seat on the same plane; a plunger which is movable in the axial direction between the first and second valve seats and receives a moving pressure toward the second valve seat by a first spring having one end seated in the hollow cylinder; A fixed valve element is embedded and fixed to the end of the plunger facing the second valve seat and has an abutment surface slightly protruding from the end face of the plunger, and the fixed valve element is inserted into the end of the plunger facing the first valve seat. , a movable valve element receiving pressure to move toward the first valve seat by a second spring disposed within the plunger;
A solenoid is provided around the hollow cylinder to axially move the plunger against the first spring, and a solenoid is configured to axially move the plunger in response to the axial movement of the plunger. A three-way valve is obtained in which the mouth is opened to allow either the corresponding first or second passage to communicate with the third passage, and with such a configuration, the above-mentioned In setting the stroke width of the plunger that moves axially between the first and second valve seats, two dimensions are required: the distance from the end face of the hollow cylinder to the inner end face of the cylindrical core, and the length of the plunger. By managing this, it becomes possible to minimize the influence of dimensional tolerances and select and set the stroke width to a desired narrow width value. Hereinafter, the present invention will be explained in more detail based on embodiments shown in the accompanying drawings.

Embodiment FIG. 2 shows a longitudinal sectional view of an embodiment of the three-way valve of the present invention in which the solenoid is not energized. In FIG. 2, a cylinder 23 is held and fixed by flanges 21 and 22, a first passage 24 passing through the flange 21 is provided below the cylinder 23, and a flange 22 is provided above the cylinder 23. A second passage 25 is provided through the second passage 25, and a third passage 26 is provided adjacent to the second passage 25. In the flange 21, the cylinder 23 has a collar 27 at the upper part of the hollow cylindrical body, and a similarly cylindrical core 28 is fitted and fixed in the lower half of the hollow cylinder 23.
The flange 21 is fitted onto the lower end portion of the hollow cylinder 23, which is sealed with a sealing member 29 made of an O-ring. A sealing member 29 made of an O-ring is disposed between the flange 22 and the hollow cylinder 23 for sealing.

The core 28 described above has a protrusion-shaped first valve seat 30 formed at its inner end, and the valve port 31 communicates with the first passage 24 through a through hole 32 formed through the core 28 in the axial direction. There is. Also, above the core 28 is a hollow cylindrical plunger 3 with a microscopic cavity T in the distance.
3 is loosely fitted into the upper half of the hollow cylinder 23, and this plunger 33 has one end seated on the stepped portion of the hollow cylinder 23, and the other end of the first spring 40 seated on the upper flange 34 of the plunger 33. By being locked, it is displaced toward the flange 22 side, that is, upwardly, under the moving pressure of the first spring 40. Between the upper end surface of the plunger 33 and the flange 22, a valve seat forming member 41 having a substantially disk shape is held between the flange 22 and the upper end surface of the hollow cylinder 23. The joint surface with the hollow cylinder 23 and the end surface of the raised second valve seat 42 formed in the center are formed on the same plane, and the valve port 43 communicates with the second passage 25 of the flange 22. . An annular space 43 formed around the second valve seat 42 forms a pressure passage, which will be described later, together with a groove 44 cut at an appropriate location on the periphery of the valve seat forming member 41 and a recess 45 of the flange 22. A sealing member 2 consisting of an O-ring for sealing is also provided between the valve seat forming member 41 and the flange 22.
9 are arranged.

The plunger 33 described above is loosely fitted into the hollow cylinder 23 as described above, and the plunger 33
A constriction 35 is formed between the outer circumference of the hollow cylinder 23 and the inner end surface of the hollow cylinder 23. The upper end of this narrow hole 35 communicates with the annular space 43 via a groove 36 formed in the upper flange 34 of the plunger 33, and the lower end communicates with the cavity "T" above the core 28. Further, the plunger 33 has a space in the internal axial direction, and a second valve 37 is fixed to the upper part of the space by an appropriate fixing method such as caulking, press-fitting, adhesion, or screwing. A rigid plate 38 is fixed to the lower side of the second valve element 37, and a spacer member 39 is provided on the upper side, whereby the plunger 33 is caulked and fixed from the upper surface. At this time, the upper end of the second valve element 37 extends upward, and the apex 37a slightly protrudes from the upper end surface of the plunger to come into pressure contact with the second valve seat 42 and close the valve port 43. ing. As mentioned above, the second valve element 37 is provided as a fixed valve element, but the second spring 50 is inserted below the second valve element 37, and the second valve element 37 receives the spring pressure of the second spring 50. A first valve element 51 is movably held at an end of the plunger opposite to the second valve element 37. This first valve 51 is the core 28
The plunger 33 is provided opposite to the valve port 31 of the first valve seat 30 provided at the inner end of the valve seat 30, and closes the valve port 31 when the plunger 33 moves downward in the direction of the core 28 by the excitation of the solenoid described later. . Here, since the first valve element 51 is a movable valve element and receives the spring pressure of the second spring 50, when the valve port 31 is closed, the spring pressure presses the first valve seat 30 and the first valve element 51. Complete closure with no pressure leaks is achieved.

A solenoid 52 is provided on the outer periphery of the hollow cylinder 23, and is configured to receive an excitation current from the outside via an electric wire 53.

The three-way valve of this embodiment is configured as described above, and when the solenoid 52 is not activated, the plunger 33 is displaced toward the valve seat forming member 41 under the spring pressure of the first spring 40. Fixed valve 37 slightly protruding from plunger 33
is pressed by the second valve seat 42, so that the second
The passage 25 is closed, and at this time the first passage 24 and the third passage 26 are empty T, narrow 35, kerf 36,
They are communicated via spaces 43, kerfs 44, recesses 45, and the like.

Furthermore, when the solenoid 52 is activated,
The plunger 33 is pressed against the upper end surface of the core 28 against the spring pressure of the first spring 40, so that the movable valve element 51 closes the valve port 31 of the first valve seat 30.
The second passage 25 and the third passage are space 43 and kerf 4.
4. communicated via the recess 45;

Note that FIGS. 3 and 4 show the cut grooves 36 and 4 mentioned above.
3 is a cross-sectional view taken along the - line and - line in FIG. 2 to show the configuration of No. 4; FIG.

As is clear from the above explanation of the structure and operation, according to the present invention, the space between the plunger and the core is
By fixing the end face of the second valve seat forming member on the same plane as the cylinder end face, T is determined by the difference between the distance A between the cylinder end face and the core end face and the length B of the plunger with the fixed valve element. Therefore, these two dimensional tolerances are the only factors that affect the tolerance of the empty T, that is, the tolerance width of the stroke amount of the plunger, and dimensional control is easy.
The maximum tolerance width from the standard stroke amount can be suppressed to a small value, making it possible to suppress the adsorption force of the solenoid to the necessary minimum, which is effective in downsizing the solenoid and reducing power consumption, and reducing the spring force to an appropriate level. This has the effect of making it difficult for vibrations to resonate. Note that if both the fixed and movable valves are made of resin material, a weight reduction effect can also be obtained.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of a conventional three-way valve having a solenoid-operated plunger, FIG. 3 and 4 are cross-sectional views taken along lines - and - in FIG. 2. 21, 22...flange, 23...hollow cylinder, 24...first passage, 25...second passage, 26
... Third passage, 28 ... Core, 30 ... First valve seat, 33 ... Plunger, 37 ... Second fixed valve element, 40 ... First spring, 41 ... Valve seat forming member, 42 ... ...Second valve seat, 51...First movable valve, 52...Solenoid.

Claims (1)

[Claims] 1. A first and a second portion held and fixed by a flange and communicating with the outside through the flange.
a hollow cylinder having passages at both ends in the axial direction and a third passage on the second passage side; a cylindrical core comprising a first valve seat having a mouth and a through hole communicating the first valve seat and the first passage; and a cylindrical core sandwiched between the flange and the hollow cylinder; A second valve seat facing the first valve seat of the cylindrical core in the axial direction is connected to the second valve seat of the cylindrical core.
a valve seat member formed at the inner end of the passage and forming a joint surface with the hollow cylinder and the second valve seat end surface on the same plane, and installed inside the hollow cylinder,
a plunger which is movable in the axial direction between the first and second valve seats and receives a moving pressure toward the second valve seat by a first spring having one end seated in the hollow cylinder; A fixed valve element is embedded and fixed to the end of the plunger facing the second valve seat and has an abutment surface slightly protruding from the end face of the plunger, and the fixed valve element is inserted into the end of the plunger facing the first valve seat. , a movable valve element receiving pressure to move toward the first valve seat by a second spring disposed within the plunger; and an axis of the plunger around the hollow cylinder against the first spring. The valve opening of either the first or second valve seat is opened in response to the axial movement of the plunger to open the corresponding first or second passage. A three-way valve, characterized in that it communicates with a third passage. 2. The three-way valve according to claim 1, wherein the first valve seat is formed to protrude from the inner end of the cylindrical core toward the movable valve element. 3. In the three-way valve according to claim 1, the second valve seat is formed in a raised manner on the substantially disk-shaped valve seat forming member held between the flange and the end surface of the hollow cylinder. A three-way valve formed by a circular protrusion. 4. The three-way valve according to claim 1, wherein the fixed valve element is made of a hard resin material.