JP3944967B2 - Hot water flow control valve for vehicle air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement structure Oite sealing packing the rotary type hot water flow control valve with a rotatable valve member for controlling the hot water flow rate in an air conditioning system for vehicles.
[0002]
[Prior art]
Conventionally, in a rotary flow control valve having such a rotatable valve body, a sealing action is obtained by bringing a seal packing into pressure contact with the outer peripheral surface of the rotatable valve body. In that case, an arc-shaped seal projection is provided on the seal packing, or a wiper for preventing entry of foreign matter (such as cast sand in the hot water circuit) in front of the seal projection (on the hot water side). Protrusion parts are set to maintain and improve the sealing function.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional structure, even if the wiper projection is set, it is not possible to completely prevent the entry of foreign matter, so that the foreign matter is stagnated between the wiper projection and the sealing projection, and this foreign matter There is a problem in that it is caught in the tip seal portion of the seal projection, obstructing the sealing function of the seal packing and greatly deteriorating the durability life of the seal packing.
[0004]
The present invention has been made in view of the above points, and in a rotary type hot water flow rate control valve having a rotatable valve body for controlling the hot water flow rate in a vehicle air conditioner , the sealing function and durability life of the seal packing are achieved. The purpose is to improve.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the passage opening area between the hot water inlet (2) and the hot water outlet (3) is controlled by the rotation of the valve body (5). In the flow rate control valve for controlling the flow rate of hot water to the heating heat exchanger (16) of the air conditioner for heating, the valve body is attached to the seal packing (7) that presses against the circular outer peripheral surface of the rotatable valve body (5). (5) Providing a sealing projection (11) projecting toward the circular outer peripheral surface,
The distal end side of the sealing projection (11), the circle of the valve element and the concave arcuate along the circular outer peripheral surface (5) (12), a valve disc in the arcuate concave surface (12) (5) Convex curved surfaces located on both sides in the circumferential direction are formed, the cross-sectional area of the sealing projection (11) is increased, the rigidity is increased, and the elastic deformation of the sealing projection (11) hardly occurs. And
The arcuate concave surface (12) is brought into surface contact with the circular outer peripheral surface of the valve body (5), and the contact length (L) of the surface contact portion is set in the range of 1.0 to 4.0 mm. It is a feature.
[0006]
According to this, by sealing protrusions of the sealing gasket (7) (11) arc-shaped concave surface (12) surface contact portion of the contact length in the (L) is more than 1.0 mm, the seal The sealing function can be improved by expanding the area.
In addition, the cross-sectional area of the sealing projection (11) is increased, the rigidity is increased, and the elastic deformation of the sealing projection (11) is less likely to occur. As a result, the biting of foreign matter into the sealing projection (11) is reduced, and the durability life of the sealing packing (7) can be improved.
[0007]
Further, by reducing the contact length (L) to 4.0 mm or less, the sliding area between the sealing projection (11) and the outer peripheral surface of the valve body (5) is reduced, and the valve body (5) The rotational operation force can be reduced .
[0008]
If the low friction layer (13) is provided on the surface of the sealing projection (11) as in the second aspect of the invention, the sealing projection (11) and the outer peripheral surface of the valve body (5) The frictional resistance between the two can be effectively reduced. Therefore, the turning operation force of the valve body 5 can be further reduced.
Further, since the frictional resistance is reduced, the external force applied from the valve body (5) to the sealing projection (11) during the rotation of the valve body (5) is also reduced, so that the elastic deformation of the sealing projection (11) is achieved. Can be further reduced, and the durable life of the seal packing (7) can be further improved.
[0009]
The said low friction layer can be comprised with a fluororesin sheet | seat (13) like invention of Claim 3 . In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show an embodiment in which the present invention is applied to a hot water flow rate control valve in a vehicle air conditioner. First, the overall configuration of the hot water flow rate control valve V will be described with reference to FIG. The hot water inlet 2 and the hot water outlet 3 are integrally molded by a resin valve housing. A substantially cylindrical valve storage chamber 4 extending in the direction perpendicular to the paper surface of FIG. 1 is formed at an intermediate portion between the hot water inlet 2 and the hot water outlet 3.
[0011]
And the valve body 5 is accommodated in the valve storage chamber 4 so that rotation is possible. The valve body 5 is also made of resin and is formed in a substantially cylindrical shape extending in the direction perpendicular to the paper surface of FIG. The valve body 5 is provided with a flow rate control hole 6 penetrating in the radial direction. Further, the valve body 5 is integrally provided with an operation shaft (not shown) protruding outside the valve housing 1, and the valve body 5 is rotated to a predetermined rotation position via the operation shaft. It has become.
[0012]
Further, inside the valve storage chamber 4, a seal packing 7 made of rubber (elastic body) is disposed at the outlet side portion of the flow rate control hole 6 of the valve body 5. The seal packing 7 is formed in a curved shape along the outer peripheral surface of the valve body 5, and an opening 8 having a size capable of fully opening the opening on the outlet side of the flow rate control hole 6 is formed at the center thereof. Is provided.
[0013]
Further, in the seal packing 7, an annular protrusion 9 is provided on the peripheral edge on the outlet side of the opening 8, and the annular protrusion 9 is press-fitted into a holding groove 10 provided in the valve housing 1. By doing so, the seal packing 7 is held between the inner wall surface of the valve housing 1 and the outer peripheral surface of the valve body 5.
Further, a sealing projection 11 projects toward the outer peripheral surface of the valve body 5 at a portion of the sealing packing 7 that faces the outer peripheral surface of the valve body 5. The seal projection 11 is formed in an annular shape over the entire periphery of the peripheral edge of the flow rate control hole 6 of the valve body 5.
At the tip ends of the sealing projection 11, as shown enlarged in FIG. 2, the arc-shaped concave surface 12 along the circular outer peripheral surface of the valve body 5 is Yes molded, thereby sealing projection concave surface 12 arc-shaped tip end parts 11 are to be in surface contact with the circular outer peripheral surface of the valve body 5. Here, the contact length L of the surface contact portion is set in a range of 0.5 to 5 mm for the reason described later.
[0014]
Further, in order to form a low friction layer on the surface of the seal projection 11, a fluororesin sheet 13 is fixed by means such as welding. This fluororesin sheet 13 is in the form of a thin film having a thickness of about 0.1 mm.
In FIG. 1, in the hot water circuit of the vehicle air conditioner, the hot water from the vehicle engine 14 passes through the flow control valve V by the water pump 15 and flows into the heating heat exchanger 16. .
[0015]
Next, the operation in the above configuration will be described. FIG. 1 shows that the outlet side of the flow rate control hole 6 of the valve body 5 communicates with the opening 8 of the seal packing 7 held and fixed to the valve housing 1 in a fully opened state. ing. Therefore, in the hot water circuit of the vehicle air conditioner, the hot water from the vehicle engine 14 passes through the flow control valve V and flows into the heating heat exchanger 16 at the maximum flow rate.
[0016]
Then, when the valve body 5 is rotated clockwise from the illustrated state of FIG. 1, the opening area between the opening 8 of the seal packing 7 and the outlet side of the flow rate control hole 6 of the valve body 5 is reduced. The hot water flow rate to the heating heat exchanger is controlled, and the heating capacity can be controlled.
By the way, in the flow rate control valve V that performs the above-described hot water flow rate control action, the seal packing 7 is provided with a seal projection 11 that protrudes toward the circular outer peripheral surface of the valve body 5, and the seal projection 11 by molding an arcuate concave surface 12 along the circular outer peripheral surface of the valve body 5 on the distal end side, thereby surface-contact the distal end side of the sealing projection 11 on the circular outer peripheral surface of the valve body 5.
[0017]
As described above, as a result of bringing the distal end side of the sealing projection 11 into surface contact with the outer peripheral surface of the valve body 5, the sealing area of the sealing projection 11 made of rubber is expanded, and the sealing function can be improved. In addition, the increase in the cross-sectional area of the sealing projection 11 increases the rigidity of the sealing projection 11 and makes it difficult for the sealing projection 11 to be elastically deformed. As a result, it is difficult for the foreign matter to bite, and the durable life of the seal packing 7 can be improved.
[0018]
Further, since the fluororesin sheet 13 forming a low friction layer is fixed to the surface of the sealing projection 11, the frictional resistance between the sealing projection 11 and the outer peripheral surface of the valve body 5 is effectively reduced. Can be reduced. Therefore, the turning operation force (operation torque) of the valve body 5 can be reduced, and the operability of the valve body 5 can be improved.
In addition, the rigidity of the sealing projection 11 is further increased due to the fixing of the fluororesin sheet 13, and the external force applied to the sealing projection 11 from the valve body 5 during the rotation operation of the valve body 5 is reduced due to the reduction of the frictional resistance. Therefore, the elastic deformation of the seal projection 11 can be further reduced, and the durability life of the seal packing 7 can be further improved.
[0019]
The present inventor has a concave surface 12 arc-shaped tip end of the sealing projection 11, the surface contact portion of the contact length of the circular outer peripheral surface of the valve body 5 (the circumferential direction of the contact length) for L, An experimental study was conducted on the relationship between the rotational operation force of the valve body 5 and the durability life of the seal packing 7, and it was found that the relationship shown in FIG.
That is, FIG. 3 shows the rotating operation force of the valve body 5 and the durability life of the seal packing 7 on the vertical axis, and the contact length L of the surface contact portion on the horizontal axis. Here, as an evaluation method of the durable life of the packing 7, for example, a minute amount (0.1 to 0.2 g / liter) of casting sand in warm water (temperature: 90 ° C., 50% antifreeze mixed). Are mixed and flown through the hot water circuit of the hot water flow rate control valve V, and the valve body 5 is repeatedly operated between the fully closed state and the fully open state. The number of opening and closing of the valve body when the amount of hot water leakage in the fully closed state of the valve body 5 reaches a predetermined amount is defined as the durable life of the packing 7.
[0020]
As can be understood from FIG. 3, when the contact length L is smaller than 0.5 mm, the durable life of the seal packing 7 is rapidly reduced. It is considered that this is because the rigidity of the sealing projection 11 is lowered, and the elastic deformation of the sealing projection 11 is likely to occur. As a result, the durability life of the packing 7 is reduced.
Moreover, when the contact length L is larger than 5.0 mm, the rotational operation force of the valve body 5 increases, which is not preferable. Therefore, the contact length L is preferably set in the range of 0.5 to 5.0 mm. Furthermore, if the contact length L is set in the range of 1.0 to 4.0 mm, it is more preferable from the viewpoint of the rotational operation force of the valve body 5 and the durability life of the seal packing 7.
[0021]
In the above embodiment, the case where the present invention is applied to the warm water flow control valve of the vehicle air conditioner has been described. However, the present invention is not limited to the control of the warm water flow rate, and the present invention can be widely applied in various applications. It is.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall configuration of a flow control valve in an embodiment of the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is a characteristic diagram showing the effect of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Valve housing, 5 ... Valve body, 7 ... Sealing packing,
DESCRIPTION OF SYMBOLS 11 ... Projection part for sealing, 12 ... Arc-shaped surface, 13 ... Fluororesin sheet.

Claims (4)

A valve housing (1) having an inlet (2) and an outlet (3) for hot water , and a valve body (5) having a circular outer peripheral surface rotatably accommodated in the valve housing (1);
A seal packing (7) provided inside the valve housing (1) and pressed against the circular outer peripheral surface of the valve body (5);
The flow rate of the hot water to the heating heat exchanger (16) of the vehicle air conditioner is controlled by controlling the passage opening area between the inlet (2) and the outlet (3) by the rotation of the valve body (5). In the warm water flow control valve of the vehicle air conditioner that controls
The seal packing (7) is provided with a seal protrusion (11) protruding toward the circular outer peripheral surface of the valve body (5),
The distal end side of the sealing projection (11), the valve body (5) a concave arcuate along the circular outer peripheral surface (12), said valve body in the arcuate concave surface (12) (5) And convex curved surfaces located on both sides in the circumferential direction are formed, the sectional area of the sealing projection (11) is increased, the rigidity is increased, and the sealing projection (11) is elastically deformed. It ’s hard to happen,
The arcuate concave surface (12) was brought into surface contact with the circular outer peripheral surface of the valve body (5), and the contact length (L) of the surface contact portion was set in the range of 1.0 to 4.0 mm. A warm water flow rate control valve for a vehicle air conditioner . The hot water flow rate control valve for a vehicle air conditioner according to claim 1, wherein a low friction layer (13) is provided on a surface of the sealing projection (11). The warm water flow rate control valve for a vehicle air conditioner according to claim 2, wherein the low friction layer is a fluororesin sheet (13). The hot water flow rate control valve (V) according to any one of claims 1 to 3 is provided, and the hot water flow rate control valve (V) controls the hot water flow rate to the heating heat exchanger (16). An air conditioner for a vehicle.

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