JPH0438892B2 - - 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 an automobile radiator.

[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 inside the radiator tank.

A communication hole is bored approximately at 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.

The purpose of this pressure regulating valve is to release this pressure from the communication hole when the pressure inside the radiator tank is below a predetermined pressure (at least below the pressure corresponding to the boiling point) and maintain the inside of the radiator tank at atmospheric pressure. Normally, it moves to the valve open position due to its own weight. Then, when the steam pressure in 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 closes and blocks the communication hole. .

[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.

In other words, when the dynamic pressure of the cooling water in the radiator tank rises instantaneously, the pressure regulating valve closes due to the dynamic pressure, and even after the instantaneous rise in dynamic pressure disappears, the pressure inside the radiator tank increases. The pressure regulating valve remains closed due to the static pressure.
The pressure inside the radiator tank is normally above atmospheric pressure when the engine is running, so once
If the pressure regulating valve closes due to a momentary pressure increase, it will remain closed due to the normal pressure within the radiator tank.

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

[Means for solving problems]

Therefore, in order to solve the above problems, the present invention has the following features:
The pressure regulating valve that opens and closes the communication hole is provided with a pressure regulating valve biasing spring that biases the pressure regulating valve in the valve opening direction with a predetermined force.

[Function] Therefore, since the pressure regulating valve is biased in the opening direction by a predetermined force, it will not close even if the pressure in the radiator tank increases momentarily, and the above-mentioned predetermined pressure will be maintained. When the pressure is below this value, the pressure inside the radiator tank is released to the outside through the communication hole.

〔Effect of the invention〕

Therefore, since no excess pressure remains in the radiator tank, there is no need to worry about pressure damage to the radiator tank wall or tube wall, and it is possible to further reduce the thickness of each wall. .

〔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 cylindrical body 2 connected to the intermediate outer wall of the inner cylindrical body 201 and arranged so as to surround the outer periphery of the inner cylindrical body 201.
It consists of 03.

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 covering the outer periphery of the cap 100 and engaging the bent claw portion 105 with the flange portion 205 .

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 so that they cannot 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 is welded to the inner cover 107 and the inner cover 107. Holding board 1
It is rotatable relative to 13.

A spring plate 114 made of a thin metal plate is sandwiched between the outer cover 101 and the inner cover 107. Since this leaf spring 114 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. This bottom plate 120 has a stepped cup shape and is arranged to face the inner lid 107.

The bottom plate 120 includes a bottom part 121 and a side wall part 1 that stands up perpendicularly from the outer edge of the bottom part 121.
23, a plane part 125 extending horizontally from the end of this side wall part 123, a flange part 127 standing vertically from the outer edge of this plane part 125, this flange part 1
The locking part 12 protrudes horizontally from the tip of 27.
It has 9.

The outer diameters of the bottom part 121 and the side wall part 123 are set smaller than the inner diameter of the inner cylinder body 201, and the bottom part 121 and the side wall part 123 are located inside the inner cylinder 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. As a result, 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.
While serving as the outer cover and guide surface, 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 through hole passing through the upper and lower surfaces is bored approximately at the center of the bottom portion 121, and a generally cylindrical center wall 133 is formed on the surface of the bottom portion 121 on the inner lid 107 side so as to surround the through hole. is formed. This central wall 133 extends upward, and an annular locking portion 134 extending inward of the through hole is formed 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 regulating valve 140 is
It consists of a disk-shaped flat plate part 141 and a center rod part 143 protruding from the center of this flat plate part 141. A pressure regulating gasket 147 is attached to the surface of the flat plate portion 141 on the bottom plate 120 side. The center rod portion 143 has a two-step tapered shape that becomes thinner toward the tip, and is inserted into the center wall 133 with a predetermined gap therebetween.

A stop plate 145 is fitted to the tip of the center rod portion 143, and the pressure regulating valve 140 is connected to the center wall 133.
Prevents it from falling out from inside.

Since the outer diameter of the center rod portion 143 is smaller than the inner diameter of the center wall 133 by a predetermined amount, a predetermined gap is secured between the two, and this predetermined gap is between the inside of the upper tank 5 and the top surface of the bottom plate 120. A communication path 150 is formed to communicate with each other.

A pressure regulating valve 140 is disposed between the lower surface of the locking portion 134 of the center wall 133 and the step shoulder of the center rod portion 143 having a two-step tapered shape. A pressure regulating valve biasing spring 148 is disposed to bias the pressure regulating valve. This pressure regulating valve biasing spring 148 has only a relatively weak spring force, and when the pressure in the upper tank 5 exceeds approximately 0.4 to 0.6 kg/cm ² , the pressure regulating valve 140 is biased in the closing direction. The pushing force becomes larger than the biasing force of the biasing spring 148, and the pressure regulating valve 140 moves in the valve closing direction. That is, the flow rate of the steam passing through the communication path 150 increases, and the resistance force increases in proportion to the square of this flow rate, so that the pressure regulating valve 140 closes. still,
When the engine is rapidly accelerated or revved, the water pump (not shown) that circulates the cooling water rotates rapidly, causing the pressure inside the upper tank 5 to drop to approximately
It increases by 0.4-0.6Kg/ ^cm2 .

Further, when the pressure regulating valve 140 is pushed upward in the figure and the pressure regulating gasket 147 is seated on the lower surface of the bottom portion 121, communication in the communication passage 150 is cut off.

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 a constriction plate 55 from the outside. By descending, the core plate 3 and the upper tank 5 are connected.

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.

Therefore, the pressure inside the upper tank 5 is reduced to the pressure regulating valve 14.
When the pressure decreases below the pressure pushing up 0, the pressure regulating valve 140 moves downward in the figure, and the pressure regulating gasket 147 separates from the bottom surface 121 of the bottom plate 120. As a result, pressure regulating valve 1
A communication path 150 formed between the center rod portion 143 of the 40 and the center wall 133 communicates with each other. When the pressure inside the upper tank 5 further drops below atmospheric pressure, the cooling water stored in the reserve tank is sucked into the upper tank 5 via the pipe 10, the space above the bottom plate 120, and the communication passage 150. .

On the other hand, when the engine starts, etc., the pressure in the upper tank 5 and the pressure steam passing through the communication passage 150 cause the pressure regulating valve 140 to be sucked upward, which is a pressure corresponding to the biasing force of the pressure regulating valve biasing spring. When the pressure becomes higher, the pressure regulating valve 140 moves toward the bottom part 121 of the bottom plate 120. That is, the pressure regulating gasket 147 comes into close contact with the bottom surface portion 121, and the communication path 150 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 continues between the pressure seal seat surface 202 and the outer cylindrical body 2.
03 and the inner cylindrical body 201 and the pipe 9
flows into the reserve tank via the

When the engine (not shown) suddenly accelerates or starts running, the water pump that circulates the engine cooling water rotates rapidly, and as a result, the system pressure inside the radiator, including inside the upper tank 5, rises instantaneously. Sometimes. However, in this example, in response to this increased pressure, the pressure regulating valve 140 does not close due to the biasing force of the pressure regulating valve biasing spring 148 and remains open. The increased pressure is released to the reserve tank side through the communication path 150.

Next, the force acting on the positive pressure valve body (bottom plate 120) in this 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. In other words, 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.

In this way, 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. Therefore, the positive pressure valve body is always seated well, and seating performance can be improved.

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.

In the above-described embodiment, the pressure regulating gasket 147 attached to the pressure regulating valve 140 is a flat ring gasket, but the shape is not limited to such a shape. You can also use it as

[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. 2 is a schematic diagram showing an embodiment of the invention. 5...Upper tank, 101...Outer lid, 107...
Inner lid, 120...Coil 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 rotatably connected to the outer cover; and a sealing member that is disposed opposite to the inner cover and is movable in the axial direction, and that is connected to a surface opposite to the inner cover. a positive pressure valve body having a seal member joint surface of the positive pressure valve body;
a sealing member seated on a sealing surface of the water inlet pipe; a spring means for biasing the positive pressure valve element toward the sealing surface of the water inlet pipe; A radiator for an automobile that includes a pressure regulating valve that communicates and shuts off a communication hole connecting an upper space and a lower space, and a pressure regulating valve biasing spring that biases the pressure regulating valve in the valve opening direction with a predetermined force. Cap. 2 One end of the spring means is in contact with the inner cover, and the other end is on the extension surface of the sealing member joint surface of the positive pressure valve body, or at a position opposite to the inner cover from this extension surface, and the positive pressure valve is in contact with the inner cover. A radiator cap for an automobile according to claim 1, which abuts against the radiator cap.