JP3545997B2 - Wax-type thermoresponsive control valve for engine refrigerant circuit - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, an improvement in a wax-type thermally responsive control valve installed on a refrigerant circulation circuit that circulates refrigerant (cooling water) of an automobile engine via a radiator circuit and a bypass circuit.
[0002]
[Prior art]
In general, in an automobile or the like, when traveling, high-temperature cooling water from the engine is cooled by a radiator by the pressure of a water pump, and the low-temperature cooling water is resupplied into a water jacket of the engine to cool the engine. A coolant circulation circuit is provided, and a wax-type thermally responsive control valve for adjusting the flow rate and temperature of the cooling water to the engine is provided on the coolant circulation circuit.
[0003]
Conventionally, as such a wax-type thermally responsive control valve, for example, one having a configuration as disclosed in Japanese Patent Application Laid-Open No. H10-19160 (prior art) filed and published by the present applicant has been proposed. Proposed. In the invention described in this prior art, a valve body is installed via a seal packing in a cooling water pipe to an engine. The valve body is provided with an annular valve seat through which cooling water can flow, and a cylindrical valve member whose outer peripheral portion slides on an inner peripheral portion of the annular valve seat within a predetermined valve opening stroke range so as to freely open and close. The annular valve seat is provided with a rubber annular seal on the outer peripheral side of the cylindrical valve body where the inner peripheral portion of the annular valve seat is in sliding contact with the annular valve seat. The valve is always urged in the downstream direction by the force to maintain the valve closed state.
[0004]
Further, as disclosed in, for example, Japanese Patent Publication No. 61-20697, the cylindrical valve element is automatically opened and closed by being linked with a wax-type thermally responsive expansion and contraction element. The thermally responsive expansion / contraction element has a wax responsive to a change in the temperature of the cooling water flowing through the refrigerant circuit in the cylindrical housing, and a plunger driven to expand and contract by expansion / contraction of the wax.
[0005]
That is, the above-mentioned wax type thermoresponsive control valve is mainly installed on the radiator circuit on the engine outlet side, and when the cooling water from the engine exceeds a desired set temperature, for example, 60 ° C., the high-temperature cooling water As the temperature rises, the expansion of the wax constituting the thermally responsive expansion and contraction element causes the plunger to extend in the axial direction, and the extension of the plunger causes the cylindrical housing to relatively move, thereby forming the cylindrical member. The valve body is moved in the direction away from the annular valve seat (valve opening direction) within a predetermined valve opening stroke range against the urging force of the spring.
[0006]
[Problems to be solved by the invention]
However, in the above-described conventional wax-type thermally responsive control valve, when the temperature of the cooling water from the engine rises rapidly and the pressure of the water pump is high, as shown by a solid line in FIG. In a predetermined valve-opening stroke range L of the valve element, an initial valve-opening stroke range L1, for example, from 3 to 4 mm to a complete valve-opening stroke range L2, for example, 8 to 10 mm, remains in the radiator and the bypass circuit. The measured low-temperature cooling water flows into the water jacket of the engine at a stretch at an excessive flow rate Q of, for example, 250 to 300 L (liter) / min. As a result, overshoot and hunting of the water temperature occur. In particular, when the temperature range of the water temperature hunting is large, such as during a warm-up operation in winter, the entire cooling system of the engine is adversely affected.
[0007]
Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-305787, a plurality of notches are formed in the circumferential direction of the inner peripheral surface of a rubber annular seal provided on the outer peripheral side of a cylindrical valve body. The cooling water is formed in the water jacket of the engine by forming a small amount of cooling water in the initial valve opening stroke range L1 of the cylindrical valve body as shown by a dotted line in FIG. There has been proposed a configuration having a configuration in which a large amount of low-temperature cooling water is prevented from flowing at once. However, in such a wax-type thermally responsive control valve, since the cylindrical valve body is press-molded with a sheet metal or the like, a notch groove formed in a rubber annular seal provided on an outer peripheral portion of the cylindrical valve body is formed. It is difficult to obtain dimensional accuracy of the shape, and there are many variations in products. Thereby, not only the flow rate of the cooling water in the initial valve opening stroke range L1 of the cylindrical valve body becomes unstable, but also in terms of structure, the flow rate adjustment in the range of 30 to 40 L (liter) / min is limited. Therefore, it is difficult to reliably prevent the occurrence of water temperature hunting.
[0008]
The present invention has been made in view of the above circumstances, and prevents the supply of excessive low-temperature cooling water to an engine in the initial valve opening stroke range of a cylindrical valve body, thereby reliably preventing the occurrence of water temperature hunting. It is an object of the present invention to provide a wax-type thermoresponsive control valve for an engine refrigerant circuit that can be used.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention includes a valve body installed on an engine refrigerant circuit, and the valve body includes an annular valve seat through which refrigerant can flow, and an inner peripheral portion of the annular valve seat. The outer peripheral portion has a tubular valve body that slides and opens and closes freely in a predetermined valve opening stroke range, and a wax-type thermally responsive expansion / contraction element that drives the tubular valve body according to the temperature of the refrigerant. In a wax-type thermally responsive control valve for an engine refrigerant circuit in which a rubber annular seal is interposed between sliding contact surfaces of a cylindrical valve body and an annular valve seat, a rubber annular ring is provided on an inner peripheral side of the annular valve seat. A plurality of seals are integrally provided by vulcanization molding, and a small amount of refrigerant can flow out in the initial valve opening stroke range of the cylindrical valve body at a desired interval in the circumferential direction on the inner peripheral surface of the rubber annular seal. formed toward the refrigerant outflow direction downstream of the notch groove from the upstream side of, and, prior to A substantially inward portion of the inner peripheral surface of the rubber annular seal is integrally formed with an inward convex portion that slides on the sliding surface of the cylindrical valve body in a circumferential direction. A part of the front end side of each notch is provided so as to be located on the downstream side in the refrigerant outflow direction, and further, each of the notches has a steeply inclined surface having a deep upstream groove depth in a vertical cross section, A notched groove having a gentle slope that is bent toward the inner peripheral surface after passing through the convex portion is characterized.
[0010]
Here, in the present invention, the shape of the notch groove is a rectangular shape having a uniform width in the refrigerant outflow direction, or a substantially inverted U-shape in which the tip is an R surface, or in the refrigerant outflow direction. The tip portion has a tapered triangular shape. When each of the cutout grooves has a configuration in which the cross-sectional area gradually decreases in the refrigerant outflow direction (downstream side), a small amount of refrigerant can flow in the downstream direction in the early stage of valve opening.
[0011]
That is, in the present invention, by adopting the above configuration, a rubber annular seal is integrally provided on the inner peripheral side of the annular valve seat by vulcanization integral molding, so that the notch groove is formed by a rubber mold. It becomes possible to mold together with the vulcanization molding of the annular seal, the dimensional accuracy of the shape of the notch groove is improved, and the flow rate of the cooling water in the initial valve opening stroke range of the cylindrical valve body is stabilized even at a minute flow rate. As described above, since the notch groove is formed together with the vulcanization molding of the rubber annular seal by the mold, it is possible to reduce the variation in the product as before.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a reference embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. FIG. 1 schematically shows an entire configuration of a wax-type thermally responsive control valve for an engine refrigerant circulation circuit according to a reference embodiment of the present invention , from a valve body 1 installed in a pipe P forming an engine refrigerant circulation circuit. Become. The valve body 1 is composed of an upper casing 1a, a lower casing 1b, and an annular member 1c for fixing each of the casings. In addition to the seal gasket 2 which is assembled in a fixed manner, an annular valve seat 3 through which cooling water W can pass is provided on the inner peripheral portion of the annular member 1c, and the seal gasket 3 is provided on the fixing flange 3a of the outer peripheral portion. 2 is fixed.
[0013]
As shown in FIG. 3, the annular member 1c is formed by pressing a steel plate to form an annular fixing flange 3a and a vertical cylinder 4 that is bent and connected upward to the inner periphery of the flange 3a. And an upper flange 3e that is bent and connected inward at the upper end of the vertical cylinder 3d. A plurality of communication holes 3f are provided in the vertical cylinder 4 at intervals in a circumferential direction of the vertical cylinder 4, and a sealing annular rubber material main body 5b fixed to the inner surface of the vertical cylinder 4 and the lower surface of the upper flange 3e; The outer peripheral surface of the vertical cylinder 4 and the auxiliary annular rubber material 5c fixed to the inner peripheral side of the upper flange 3e and the fixing flange 3a are connected via the rubber material filled in the communication hole 3f to form a rubber. An annular seal 5 is formed.
[0014]
As shown in FIG. 2, a vertical cylinder 4 made of a cylindrical standing piece is integrally formed on the inner peripheral portion 3 b of the annular member 1 c along the circumferential direction. A rubber annular valve seat 3 in which a part of a sealing annular rubber material main body 5c is wound around a lower surface 3c side of a connection portion between a vertical cylinder 4 and a fixing flange 3a is fixed by integral molding.
[0015]
An inner peripheral surface 5a of the rubber annular seal 5 has an inward convex portion having a substantially V-shaped vertical cross section at an intermediate portion (substantially the center portion in the illustrated case) in the refrigerant outflow direction Y between the upstream side and the downstream side. Portions (lip portions) 6 are integrally formed so as to protrude in the circumferential direction, and a plurality of notched grooves 7 are arranged at a desired interval in the circumferential direction (four at an equal angular interval of 90 degrees in the illustrated case). The notch groove 7 has a front end portion 7a side partly facing the inwardly protruding portion 6 facing the downstream side in the refrigerant outflow direction Y. That is, an upstream inclined surface 6a connected to the cylindrical inner peripheral surface 5a and inclined so as to gradually project inward from the upstream direction to the downstream direction, and is connected in a bent state to the upstream inclined surface 6a and extends from the upstream direction to the downstream direction. A downstream inclined surface 6b which is inclined so as to expand the diameter and is connected to the inner peripheral surface 5a, and a tip end of the notch groove 7 is located further downstream than the downstream inclined surface 6b. It is located on the inner peripheral surface 5a. Further, the cross section of each of the notch grooves 7 is provided so as to gradually decrease in the downstream direction. When the inwardly protruding portion 6 is in contact with the sliding contact piece 8b of the tubular valve body 8 described later, the inwardly protruding portion 6 is contacted in a state of being crushed by about 0.2 mm to 0.4 mm.
[0016]
On the other hand, a cylindrical valve element 8 is disposed on the inner peripheral part 3b of the annular member 1c, and a flange part 8a is provided on the downstream outer peripheral part of the cylindrical valve element 8 and rises vertically from the flange part 8a. A cylindrical sliding contact piece 8b is formed. The tubular valve body 8 is always urged in the downstream direction in the refrigerant outflow direction Y by a spring 9 composed of a compression coil spring interposed between the lower casing 1b and the tubular valve body 8 in a compressed state. The flange portion 8a is brought into contact with a part of the annular valve seat surface of the rubber annular seal 5 fixed to the upstream lower surface 3c side of the annular member 1c with the cylindrical sliding contact piece therebetween. 8b is brought into sliding contact with the inward convex portion 6 on the inner peripheral surface 5a side of the rubber annular seal 5 fixed to the inner peripheral portion 3b of the annular member 1c, so that the closed state of the annular valve seat 3 is maintained. It is supposed to be.
[0017]
Further, a wax-type thermally responsive expansion and contraction element 10 is assembled to the cylindrical valve body 8, and the thermally responsive expansion and contraction element 10 is a wax responsive to a temperature change of the cooling water W flowing in the refrigerant circulation circuit in the cylindrical housing 11. And a plunger 13 which expands / contracts (retreats) via a rubber bottomed sleeve when the wax 12 expands / contracts. That is, when the valve is opened, the plunger 13 extends in the axial direction due to the expansion of the wax 12 constituting the thermally responsive expansion / contraction element 10 due to the temperature rise of the cooling water W. Then, the cylindrical housing 11 moves relatively upstream by the extension operation of the plunger 13, and the cylindrical valve body 8 moves the annular valve seat 8 within a predetermined valve opening stroke range L against the urging force of the spring 9. By moving in the direction (valve-opening direction) X away from 3, the valve-opening operation is automatically performed.
[0018]
Incidentally, as shown in FIG. 3, a mold (not shown) was used for the vertical cylinder 4 of the outer peripheral edge 3a and the inner peripheral part 3b of the annular member 1c assembled to the valve body 1 as described above. The seal packing 2 and the rubber annular seal 5 are integrally molded and fixed by vulcanization integral molding, and at the same time, the cutout groove 7 is molded in the rubber annular seal 5. This makes it possible to improve the dimensional accuracy of the shape of the cutout groove 7 formed in the rubber annular seal 5 and to reduce the variation in the product.
[0019]
In this case, the shape of the notch groove 7 is a rectangular shape having the same width in the refrigerant outflow direction Y as shown in FIG. 4A, and the downstream end 7a as shown in FIG. The shape of the surface is substantially inverted U-shaped, or the downstream distal end portion 7a is formed by changing to an arbitrary shape such as a tapered triangular shape in the refrigerant outflow direction Y as shown in FIG. The flow rate Q of the cooling water W can be easily adjusted by adjusting the depth, width, number, and the like of the notch grooves 7. In addition, as shown by one-point broken line A, two-point broken line B, and three-point broken line C in FIG. 5, corresponding to the forms of FIGS. In the valve opening stroke range L, the flow rate Q of the cooling water W in the range from the initial valve opening stroke range L1 to the complete valve opening stroke range L2 flows out in a range of, for example, 3 to 10 L (liter) / min. And a more stable outflow than that of a conventional wax-type thermally responsive control valve as shown by a solid line and a dotted line in FIG.
[0020]
In the above-described embodiment, the form of the cutout groove 7 which is uniformly inclined from the upstream side to the downstream side is shown. However, when the present invention is carried out, as shown in FIG. And a notched groove 7 having a gentle inclined surface 7c which is bent toward the inner peripheral side from a point beyond the inwardly protruding portion 6. Since the volume is increased, the amount of refrigerant flowing to the downstream side can be further stabilized even in the initial valve opening state.
[0021]
When implementing the present invention, the inwardly protruding portion 6 may have an obtuse angled V-shape or trapezoidal cross section, and the notch portion 7 may have one or more even or odd numbers of equal angles or odd numbers. They may be provided at appropriate intervals.
[0022]
【The invention's effect】
As described above, the wax-type thermally responsive control valve for an engine refrigerant circulation circuit according to the present invention is provided with a rubber annular seal integrally on the inner peripheral side of the annular valve seat by vulcanization molding. At the time of vulcanization molding of the rubber annular seal to the annular valve seat, the notch groove can be molded by a mold. As a result, the dimensional accuracy of the shape of the notch groove can be improved, and the conventional product variation can be reduced. Accordingly, the flow rate of the cooling water in the initial valve opening stroke range of the cylindrical valve element can be stabilized even with a small amount, and thus the occurrence of water temperature hunting can be reliably prevented. Also, by changing the shape of the notch groove, the flow rate of the cooling water can be easily adjusted. Further, in the present invention, the notch groove is a notch groove having a steeply inclined surface having a deep groove depth on the upstream side and a gentle inclined surface which is bent toward the inner peripheral surface after passing the inward convex portion in the longitudinal section. Therefore, the volume of the upstream side of the notch groove is increased, so that the amount of the refrigerant flowing to the downstream side can be further stabilized even in the initial valve opening state.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing an overall configuration of a wax-type thermally responsive control valve for an engine refrigerant circulation circuit according to a reference embodiment of the present invention.
FIG. 2 is an enlarged sectional view of a main part between sliding surfaces of an annular valve seat and a cylindrical valve body.
FIG. 3 is a cross-sectional view of a principal part showing a state in which a seal packing and a rubber annular seal are attached to an annular valve seat by vulcanization molding.
FIGS. 4A, 4B, and 4C are explanatory views showing forms of cutout grooves formed in a rubber annular seal.
FIG. 5 is an explanatory diagram showing a flow rate of cooling water in a valve opening stroke range of a cylindrical valve body in comparison with a conventional wax-type thermally responsive control valve.
FIG. 6 is an explanatory sectional view showing a modified form of the notch groove.
[Explanation of symbols]
Reference Signs List 1 valve body 1a upper casing 1b lower casing 1c annular member 2 seal packing 3 annular valve seat 3a fixing annular flange 3b inner peripheral portion 3c lower surface 4 vertical cylinder 5 rubber annular seal 5a inner peripheral surface 5b sealing annular rubber material body 5c Auxiliary annular rubber material 6 Inward convex portion 6a Upstream inclined surface 6b Downstream inclined surface 7 Notch groove 7a Tip portion 7b Steep inclined surface 7c Slowly inclined surface 8 Cylindrical valve body 8a Flange portion 8b Sliding contact piece 9 Spring 10 Thermally responsive Telescopic element 11 Cylindrical housing 12 Wax 13 Plunger L Opening stroke range L1 of cylindrical valve body Initial valve opening stroke range L2 of cylindrical valve body Complete valve opening stroke range P of cylindrical valve body P Refrigerant circulation circuit (pipe)
Q Refrigerant flow rate W Refrigerant (cooling water)
X Valve opening direction Y Refrigerant outflow direction

Claims (5)

The valve body is provided on an engine refrigerant circuit. The valve body has an annular valve seat through which refrigerant can flow, and an inner peripheral portion of the annular valve seat having an outer peripheral portion within a predetermined valve opening stroke range. A tubular valve body that slides and opens and closes freely so as to be able to open and close, and a wax-type thermally responsive expansion / contraction element that drives the tubular valve body in accordance with the temperature of the refrigerant; In a wax-type thermally responsive control valve for an engine refrigerant circulation circuit having a rubber annular seal interposed between sliding contact surfaces with
A rubber annular seal is integrally provided on the inner peripheral side of the annular valve seat by vulcanization molding, and the cylindrical valve body is provided at a desired circumferential distance on an inner peripheral surface of the rubber annular seal. A plurality of notch grooves from which a small amount of refrigerant can flow out in the initial valve opening stroke range are formed from the upstream side to the refrigerant outflow direction on the downstream side , and at a substantially middle portion of the inner peripheral surface of the rubber annular seal, An inward convex portion that slides on the sliding contact surface of the cylindrical valve body is integrally formed so as to protrude in the circumferential direction, and a part of the front end of each of the notched grooves flows out of the inward convex portion as a refrigerant. The notch groove is further provided in the vertical section, and the groove depth on the upstream side is deep and steeply inclined, and the notch groove is bent toward the inner peripheral surface side after passing through the inward convex portion. A wax-type thermally responsive control valve for an engine refrigerant circuit, wherein the notch groove has a gentle slope . The wax-type thermally responsive control valve for an engine refrigerant circuit according to claim 1, wherein the notch groove has a rectangular shape having an equal width in a refrigerant outflow direction. The wax-type thermally responsive control valve for an engine refrigerant circuit according to claim 1, wherein the cutout groove has a shape of a substantially inverted U-shape with a front end having an R surface. The wax-type thermally responsive control valve for an engine refrigerant circuit according to claim 1, wherein the notch groove has a triangular shape whose tip portion is tapered in a refrigerant outflow direction. The wax-type thermally responsive control valve for an engine refrigerant circuit according to any one of claims 1 to 4, wherein the notch groove has a form in which a cross-sectional area gradually decreases in a refrigerant outflow direction.

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