JPH0437254B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radiator cap that is fitted onto a water inlet pipe of a radiator cap for an automobile.

[Conventional technology]

As an illustration of a conventional radiator cap,
For example, there is US Pat. No. 3,265,048.

In the radiator cap shown in this specification, a positive pressure valve element that closes when the pressure inside the radiator tank exceeds a certain value is seated on the seal seat of the water inlet by the biasing force of a coil spring. This positive pressure valve body is used to raise the boiling point of the cooling water in the radiator tank, and when the temperature of the cooling water reaches the boiling point at atmospheric pressure, the pressure in the radiator tank increases to the corresponding pressure (hereinafter referred to as boiling point corresponding pressure). ), the positive pressure valve body will not open. Only when the pressure rises further does the valve open, releasing the pressure steam in the radiator tank.

A communication hole is bored approximately in the center of the positive pressure valve body, and a pressure regulating valve for opening and closing this communication hole is disposed on the positive pressure valve body.

This pressure regulating valve ensures that the pressure in the radiator tank is below a specified pressure (at least below the pressure corresponding to the boiling point).
The purpose of this valve is to release this pressure through the communication hole and maintain it at atmospheric pressure within the radiator tank, and normally it moves to the open position due to its own weight. When the steam pressure inside the radiator tank rises and the force trying to move the pressure regulating valve in the closing direction exceeds the pressure regulating valve's own weight,
The pressure regulating valve is closed to block the communication hole.

Furthermore, in the conventional radiator cap, as shown in FIG. 3, the point of action of the spring that biases the positive pressure valve element in the valve closing direction is located above the sealing surface of the positive pressure valve element.

[Problem that the invention seeks to solve]

Normally, the pressure inside the radiator tank gradually increases depending on the engine operating time, but when the engine is rapidly accelerating or revving, the water pump that circulates the cooling water rotates rapidly. A phenomenon occurs in which the dynamic pressure of the cooling water in the radiator tank increases instantaneously.

While such a phenomenon occurs, conventional radiator caps have the following problems.

That is, the pressure regulating valve opens due to an instantaneous pressure increase in the radiator tank, and the pressure regulating valve remains closed even after the instantaneous pressure increase disappears. The pressure inside the radiator tank is normally higher than atmospheric pressure when the engine is running, so once the pressure regulating valve closes due to a momentary pressure rise, the normal pressure inside the radiator tank will cause the pressure to close. The valve remains closed.

In this way, if the pressure regulating valve closes before the pressure inside the radiator tank reaches the predetermined steam pressure, the pressure that should originally be released to the outside through the communication hole remains inside the radiator tank.
There is a problem in that this residual pressure acts as pressure damage on the radiator tank wall and the tube wall formed from a relatively thin plate.

Furthermore, in conventional radiator caps, the point of action of the spring that biases the positive pressure valve element in the valve closing direction is located above the sealing surface of the positive pressure valve element.
There is a problem in that the rotational moment acting on the positive pressure valve body acts in the valve opening direction of the positive pressure valve body, impairing the seating ability of the positive pressure valve body.

[Means for solving problems]

Therefore, in the present invention, focusing on the fact that the pressure inside the radiator tank has a correlation with the temperature inside the radiator tank, the regulating valve that opens and closes the communication hole is constructed from a thermally responsive member that deforms according to the temperature inside the tank. . When the temperature inside the tank section is below a predetermined value, the communication hole is opened, and when the temperature inside the tank section is above a predetermined value, the communication hole is deformed and closed.

Further, the other end of the coil spring was brought into contact with the positive pressure valve body at a position opposite to the inner cover from the sealing surface of the positive pressure valve body.

[Effect]

When the temperature inside the radiator tank is below a predetermined value, the pressure regulating valve opens the communication hole, so that the pressure steam inside the radiator tank remains exposed to the outside through the communication hole.

Only when the temperature inside the radiator tank reaches a predetermined value or higher does the pressure regulating valve close the communication hole, and the pressure inside the radiator tank increases.

Furthermore, when the positive pressure valve element opens unevenly, the urging force of the coil spring that urges the positive pressure valve element in the valve closing direction always acts on the positive pressure valve element as a rotational force in the valve closing direction.

〔Effect of the invention〕

Therefore, when the temperature inside the radiator tank is below a predetermined value, the communication hole is always open, and even if the pressure inside the radiator tank rises momentarily, the valve will not close, so any excess inside the radiator tank will be eliminated. Residual pressure can be released to the outside, and the frequency of pressurization within the radiator system including the inside of the radiator tank can be reduced. By reducing the frequency of pressurization within the radiator system, pressure damage to each component can be reduced, and further thinning of each component can be promoted.

In addition, in the present invention, the biasing force of the coil spring always acts on the positive pressure valve body as a rotational force in the valve closing direction, so the positive pressure valve body is always seated well, and seating performance can be improved. can.

Improving the seating performance of the positive pressure valve body means that the positive pressure valve body always seats on the sealing surface of the water inlet pipe in the same position, and the sealing member joined to the positive pressure valve body always sits in the same position. This means that it comes into contact with the seal seat of the water inlet. A contact groove is formed on the surface of the seal member as a permanent strain due to contact with the seal seat surface of the water inlet pipe, so if the contact position between the seal member and the seal seat surface is If the grooves are different, the abutment groove will be located at a location other than the abutment point, resulting in a problem that the seal between the seal member and the seal seat surface will be impaired.However, in the present invention, such a problem does not occur. .

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

Figure 2 is a front view of an automobile radiator.
An upper tank 5 and a lower tank 6 are connected to both ends of a plurality of tubes 1 arranged in parallel via end plates 3 and 4. Wave-shaped fins 2 are joined between the plurality of tubes 1 by means such as brazing, and promote heat exchange between the engine cooling water flowing inside the tubes 1 and the atmosphere outside the tubes 1. There is.

The upper tank 5 is formed with an introduction pipe 7 for introducing cooling water from an engine (not shown) and a water inlet pipe 9 for replenishing the engine cooling water. The water inlet pipe 9 is formed with a pipe 10 for connecting the inside of the water inlet pipe 9 and a reserve tank (not shown), and is further provided with a pipe 10 for connecting the inside of the water inlet pipe 9 and a reserve tank (not shown).
A cap 100 is fitted into the open end of the cap.

A lead-out pipe 8 is formed in the lower tank 6 to guide the cooling water flowing through the tube 1 and collected in the lower tank 6 back to the engine side.

FIG. 1 is a cross-sectional view of FIG. 2, and based on this figure, the cap 100 and water inlet 9 are
The shape of will be explained.

The water inlet 9 is connected to the inner cylinder 20 connected to the upper tank 5.
1, and an outer cylinder 203 arranged so as to surround the outer periphery of the inner cylinder 201 connected to the intermediate outer wall of the inner cylinder 201.

The open end of the inner cylindrical body 201 forms an annular positive pressure seal seating surface 202, and the open end of the outer cylindrical body 203 forms an annular fitting seal seating surface 204.
The fitting seal seat surface 204 is located above the positive pressure seal seat surface 202. In addition, the outer cylinder body 2
An annular flange portion 205 protruding radially outward is formed at the open end of 03.

The outer lid 101 of the cap 100 has a saucer shape, and has a side wall portion 103 on its outer periphery.Furthermore, a part of the tip of this side wall portion 103 has a bending claw portion bent toward the center. 105. This side wall portion 103 is a flange portion 205
The cap 100 is fitted onto the water inlet pipe 9 by engaging the bent claw portion 105 with the flange portion 205 on the outer periphery of the cap 100 .

Note that a notch (not shown) is formed in a part of the annular flange portion 205, and the outer lid 1 is bent so that the bending claw portion 105 is located in this notch.
01, the cap 100 is removed from the water inlet pipe 9.

An inner cover 107 is disposed inside the outer cover 101. This inner lid 107 also has a saucer shape, and has a side wall portion 109 on its outer periphery, and further has an engaging protrusion 111 that protrudes inward at the tip side of the side wall portion 109. .

A circular hole 102 is formed approximately at the center of the outer lid 101, and a circular recess 108 is formed approximately at the center of the inner lid 107. This circular hole 102
and the circular recess 108 face each other.
1 and the inner lid 107 are placed one on top of the other, and the two are joined by a restraining plate 113.

The restraining plate 113 has a pot shape with a flange at the outer peripheral end, and its bottom surface passes through the circular hole 102 of the outer lid 101 and into the circular recess 108 of the inner lid 107.
It is spot welded on. Therefore, the holding plate 11
3 and the inner cover 107 are welded together so that they do not move relative to each other, but since the outer cover 101 is only held between the flange of the holding plate 113 and the inner cover 107, the outer cover 101 does not move relative to the inner cover 107. and holding plate 1
It is rotatable relative to 13.

A leaf spring 113 made of a thin metal plate is sandwiched between the outer cover 101 and the inner cover 107. Since this leaf spring 113 is also simply clamped, it is rotatable relative to the outer cover 101 and the inner cover 107. Further, on the inner surface of this leaf spring 113, an annular pressure gasket 115 made of a rubber material is provided.
is attached, and when the cap 100 is fitted into the water inlet pipe 9, this presser gasket 11
5 is seated on the fitting seal seat surface 204 by the biasing force of the leaf spring 113.

A bottom plate 120, which is a positive pressure valve element, is disposed inside the inner lid 107. The bottom plate 120 has a stepped cup shape and is arranged to face the inner lid 107.

The bottom plate 120 has a disc-shaped bottom part 12.
1. A cylindrical side wall part 123 that stands up perpendicularly from the outer edge of this bottom part 121, a circular plane part 125 that extends horizontally from the end of this side wall part 123, and a cylinder that stands up perpendicularly from the outer edge of this plane part 125. It has a circular flange portion 127 and a ring-shaped locking portion 129 that protrudes from the tip of the flange portion 127 in the horizontal direction.

The outer diameters of the bottom part 121 and the side wall part 123 are set smaller than the inner diameter of the inner cylindrical body 201, and the bottom part 121 and the side wall part 123 are located inside the inner cylindrical body 201.

The flat part 125 extends slightly outward from the outer diameter of the inner cylindrical body 201, and an annular positive pressure packing 131 made of a rubber material is pasted on the bottom side of the flat part 125, which is the sealing member joint surface. It is worn. Then, this positive pressure packing 131 is connected to the positive pressure seal seat surface 2.
I will be seated in 02.

The outer diameter of the flange portion 127 is set to be slightly smaller than the inner diameter of the engagement protrusion 111 of the inner lid 107, and the outer diameter of the locking portion 129 is set to be slightly smaller than the inner diameter of the side wall portion 109 of the inner lid 107. ing. Therefore, the flange portion 127 and the locking portion 12
9 is located within the side wall portion 109 of the inner lid 107, the locking portion 129 uses the inner wall of the side wall portion 109 as a guide surface, and the engaging protrusion portion 111 is located within the flange portion 127.
The outer wall and guide surface of the bottom plate 12
0 becomes relatively movable up and down within the inner lid 107.

Further, the bottom plate 120 has a locking portion 129.
By engaging with the engagement protrusion 111, falling off downward is prevented.

A circular communication hole 122 passing through the upper and lower surfaces is bored approximately at the center of the bottom portion 121, and a generally cylindrical hole 122 is formed on the surface of the bottom portion 121 on the inner lid 107 side so as to surround the through hole. A central wall 133 is formed. This central wall 133 extends upward, and forms an engaging portion 134 having a reduced inner diameter at its upper end.

horizontal part 125, side wall part 123, bottom part 121,
A plurality of ribs 135 are formed on the surface of the center wall 133 facing the inner lid 107 in order to increase the strength of the bottom plate 120.

A coil spring 137 is arranged between the inner lid 107 and the bottom plate 120 to bias the bottom plate 120 toward the inner cylinder body 201. One end of this coil spring 137 is in contact with the inner wall surface of the inner lid, and the other end is in contact with the upper wall of the bottom surface portion 121.

A pressure regulating valve 140 is arranged on the lower surface side of the bottom plate 120. The pressure valve 140 includes a center portion 143 located within the communication hole 122, a disk-shaped disk portion 141 fixed to the end of the center rod portion 143 on the upper tank 5 side, and the disk portion 141.
A pressure regulating gasket 147 is attached to the surface of the bottom plate 120 side.

The disk portion 141 is made of a bimetal that is reversely displaced depending on the temperature inside the upper tank 5, and is connected to the center rod portion 143 at its center.
When the temperature inside the upper tank 5 is below a predetermined value, the upper tank 5 has a convex shape upward in the figure as shown in FIG. Therefore, the communication hole 122 is open.

On the other hand, when the temperature inside the upper tank 5 exceeds a predetermined value, the disk portion 141 is reversely displaced from the illustrated state to a downwardly convex shape in the figure, and the pressure regulating packing 147 deformed along this direction presses against the bottom surface portion 121. The communication hole 122 is then closed.

The inversion temperature of the disk portion 141 is set at a temperature below and in the vicinity of the boiling point of the cooling water in the upper tank 5, and in this embodiment is set at 80°C to 95°C.

Although the disk portion 141 is made of bimetal in this embodiment, it may be made of a shape memory alloy that deforms at a predetermined temperature.

A stop plate 145 is fitted to the tip of the center rod portion 143, and this stop plate 145 is attached to the engaging portion 134.
By coming into contact with the center wall 133, the pressure regulating valve 140 is prevented from falling out from inside the center wall 133.

Since the outer diameter of the center rod portion 143 is smaller than the inner diameter of the communication hole 122 by a predetermined amount, a predetermined gap is maintained between the two.

The foot portion 51, which is the open end of the upper tank 5, is fitted into a groove formed on the outer periphery of the core plate 3 via an O-ring 53, and this fitting portion is wrapped with an outwardly twisted plate 55. The core plate 3 and the upper tank 5 are connected by machining.

Note that the lower tank 6 and core plate 4 are also connected in the same manner.

Next, the operation of this embodiment will be explained. The space above the bottom plate 120 in the figure is occupied by the pipe 1.
0 communicates with a reserve tank (not shown), so the pressure is always maintained at atmospheric pressure.

As the engine operates, the temperature of the cooling water flowing into the upper tank 5 increases. If this cooling water temperature is below a predetermined value (80℃~95℃), the disc part 1
41 is in an upwardly convex state as shown in FIG.
The pressure regulating gasket 147 is separated from the bottom surface portion 121 of the bottom plate 120. As a result, the communication hole 122 formed in the bottom plate 120 communicates, and the cooling water stored in the reserve tank flows into the upper tank 5 through the pipe 10, the space above the bottom plate 120, and the communication hole 122. It gets sucked in.

After that, when the temperature of the cooling water in the upper tank 5 further increases and reaches a predetermined value (80°C to 95°C), the disc part 141 deforms into a downwardly convex state and touches the bottom part 121 of the bottom plate 120. Pressure regulating valve 1
40 is imposed. That is, the pressure regulating gasket 147 comes into close contact with the bottom surface portion 121, and the communication hole 122 is blocked.

Furthermore, the pressure within the upper tank 5 increases, and the force exerted by the bottom plate 120 upward in the figure due to this pressure becomes greater than the force exerted downward in the figure by the coil spring 137.
The bottom plate 120 moves upward in the figure.

That is, the positive pressure gasket 131 attached to the bottom plate 120 separates from the positive pressure seal seat surface 202 of the inner cylinder body 201, and the high-pressure steam in the upper tank 5 flows between the positive pressure gasket 131 and the positive pressure gasket 131. It passes between the pressure seal seat surface 202 and the outer cylinder body 2.
03 and the inner cylinder body 201 and the pipe 1
9 to the reserve tank.

Next, a second embodiment of the present invention will be described.

When the temperature inside the upper tank 5 is below a predetermined value, the disk portion 141 of the pressure regulating valve 140 is in an upwardly convex state, similar to the above-described embodiment, and the communication hole 1
22 are open.

The temperature inside the upper tank 5 rises to a predetermined value (70℃~
80°C), the disc part 1 of the pressure regulating valve 140
41 deforms from an upwardly convex state to a flat disc shape. At this time, the pressure regulating gasket 147 attached to the disc part 141 and the bottom part 1 of the bottom plate 120 are
Since a predetermined gap is formed between the communication hole 122 and the communication hole 122, the communication hole 122 remains open.

After that, when the temperature further rises and the amount of steam released to the reserve tank side through the communication hole 122 increases, the flow rate of the steam passing through the communication hole 122 also increases, and the pressure regulating valve 140 increases due to the increase in the flow rate of steam.
The pulling force increases. When this lifting force exceeds the weight of the pressure regulating valve 140, the pressure regulating valve 140 moves in the valve opening direction, and the pressure regulating gasket 147 is pressed against the bottom surface portion 121 to close the communication hole 122.

In this embodiment, the pressure regulating valve 140 is connected to the communication hole 1.
22 in the axial direction of the center rod portion 143.

Other configurations and operations are the same as in the first embodiment.

In the above-described embodiment, the pressure regulating packing 147 attached to the pressure regulating valve 140 is a flat annular packing, but the shape is not limited to such a shape. good.

Next, the force acting on the bottom plate 120 of the above-mentioned embodiment will be explained while comparing it with the conventional example.

FIG. 3 is a diagram schematically showing the conventional positive pressure valve body and the end face of the water inlet, where 501 is the end face of the water inlet, 503 is the positive pressure valve body, and arrow F ₀ indicates that the coil spring is connected to the positive pressure valve body 503. It is a biasing force.

The biasing force F ₀ of the coil spring is the positive pressure valve body 5
Since the positive pressure valve body 503 always acts in the vertical direction on the surface 505 of 03, as shown in FIG.
When the positive pressure valve body 50 opens unevenly around point O
A component force F ₁ parallel to the surface 505 acts on the surface 505 of No. 3 .

The biased opening angle of the positive pressure valve body 503 is θ, and the positive pressure valve body 50
The distance from the surface 505 of 3 to the seal 507 is D
Then, the component force F ₁ becomes F ₁ =F ₀ sin θ, and regarding the point O, a rotational moment of M ₀ =F ₁ ×D acts in the direction of arrow R in the figure.

The fact that this rotational moment M ₀ acts in the direction of arrow R means that the positive pressure valve body 503 is biased in the valve opening direction. That is, although the biasing force F ₀ originally biases the positive pressure valve body 503 in the valve closing direction, its component force F ₁ acts in the valve opening direction, and as a result,
A problem arises in that the seating ability of the positive pressure valve body 503 is impaired.

FIG. 4 is a diagram schematically showing the positive pressure valve body of the radiator cap of this embodiment and the end face of the water inlet.
Since the contact point between the coil spring and the positive pressure valve body 603 is located on the opposite side of the inner cover from the sealing surface 607 of the positive pressure valve body 603, that is, on the lower side in the figure, the point of application of the biasing force F ₀ of the coil spring is also positive. Pressure valve body 6
It is located below the sealing surface of 03.

As described in the explanation of FIG. 3, the positive pressure valve body 60
A component force F ₁ of the biasing force F ₀ is acting on the surface 605 of No. 3 in a direction parallel to the surface 605. Positive pressure valve body 60
If the vertical distance from the surface 605 of No. 3 to the extension of the sealing surface 607 is D ₁ , a rotational moment of M ₁ =F ₁ ×D ₁ acts in the direction of arrow P around point O.
That is, a rotational force in the valve closing direction acts on the positive pressure valve body 603.

Therefore, in the radiator cap of this embodiment, when the positive pressure valve element opens unevenly, the biasing force of the coil spring that biases the positive pressure valve element in the valve closing direction is always a rotational force against the positive pressure valve element in the valve closing direction. As a result, the positive pressure valve body is always properly seated.
It is possible to improve seating comfort.

Improving the seating performance of the positive pressure valve element means that the positive pressure valve element always seats on the seal seating surface of the water inlet pipe in the same position, and the seal member joined to the positive pressure valve element always sits in the same position. This means that it comes into contact with the seal seat of the water inlet pipe.
When the seal member contacts the seal seat surface of the water inlet pipe, a contact groove is formed on its surface as a permanent strain, so if the contact position between the seal member and the seal seat surface is If this were different, the abutment groove would be located at a location other than the abutment point, resulting in a problem that the seal between the seal member and the seal seat surface would be impaired, but this embodiment does not have such a problem.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the first embodiment, Fig. 2 is a - sectional view, Fig. 2 is a front view showing an automobile radiator, Fig. 3 is a schematic diagram showing a conventional example, and Fig. 4 is a sectional view of the present invention. FIG. 1 is a schematic diagram showing the invention. 5...Upper tank, 101...Outer lid, 107...
Inner lid, 120...Bottom plate (positive pressure valve body),
137...Coil spring, 140...Pressure regulating valve.

Claims (1)

[Scope of Claims] 1. A radiator cap fitted to a water inlet pipe formed in a tank portion of an automobile radiator, comprising: an outer cover that engages with the water inlet pipe; and an inner side of the outer cover. an inner cover that is joined to the outer cover so as to be relatively rotatable; and an inner cover that is disposed opposite to the inner cover so as to be movable in the axial direction, and has a seal for the water inlet pipe on a surface opposite to the inner cover. a positive pressure valve body having a sealing surface that seats on a seat surface; and a positive pressure valve body disposed between the inner cover and the positive pressure valve body, one end of which is in contact with the inner cover, and the other end of which is in contact with the positive pressure valve body. a coil spring that contacts the positive pressure valve body and biases the positive pressure valve body in a direction opposite to the inner cover; a communication hole formed in the positive pressure valve that communicates a space above and a space below the positive pressure valve body; Provided in the pressure valve body, the communication hole
and a pressure regulating valve that shuts off, the pressure regulating valve being made of a thermally responsive member that deforms according to the temperature inside the tank of the automobile radiator, and when the temperature inside the tank is below a predetermined value. The communication hole is opened, and when the temperature inside the tank portion reaches a predetermined value or more, the communication hole is deformed and closed, and the other end of the coil spring is located on the opposite side of the inner lid from the sealing surface of the positive pressure valve body. A radiator cap for an automobile that is in contact with the positive pressure valve body at a side position.