JP2004232472A - Failure prevention mechanism for pulsation damper in case of failure - Google Patents

Abstract

Provided is a pulsation damper having a simple configuration and capable of preventing fuel with a fuel pressure from leaking when a diaphragm is abnormal.
A diaphragm (3) provided between a fuel chamber (2) communicating with a fuel pipe and an atmosphere opening chamber (4) communicating with the atmosphere through a hole (5) reduces fuel pressure pulsation of the fuel pipe. Reduce. The movable plug (6) is provided in the hole, and when the diaphragm is abnormal, the movable stopper moves to the outside of the open-to-atmosphere chamber to seal the hole, whereby the hole can be sealed using the pressure itself from the fuel chamber.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pulsation damper for reducing a fuel pressure pulsation generated in a fuel pipe, and more particularly, to a mechanism for effectively preventing a fuel leak at the time of an abnormality such as deterioration and rupture of a diaphragm.
[0002]
[Prior art]
Fuel pressure pulsation is generated in a fuel pipe for supplying fuel to an engine or the like by injection of a fuel pump or an injector. This fuel pressure pulsation is undesirable because it causes a variation in the amount of discharged fuel. To reduce the pulsation, a pulsation damper as disclosed in, for example, JP-A-2000-104636 is used.
[0003]
Such a pulsation damper includes a fuel chamber communicating with the fuel delivery pipe and an air chamber communicating with the atmosphere, and supports a diaphragm partitioned into the fuel chamber and the air chamber by a spring mounted in the air chamber. ing. Since the pulsation in the fuel delivery pipe is also transmitted to the fuel chamber in the pulsation damper, the pulsation is reduced by vibration of the diaphragm against the spring.
[0004]
[Patent Document 1] JP-A-2000-104636 (FIG. 2, paragraphs 0010 to 0012, etc.)
[0005]
[Problems to be solved by the invention]
In the configuration described in the above publication, in order to prevent fuel leakage at the time of abnormality such as deterioration and breakage of the diaphragm, it is conceivable that the diaphragm is pushed toward the fuel chamber by the urging force of the spring when the diaphragm is abnormal. Thereby, the head of the screw fixed to the diaphragm through the hole in the air chamber wall is pressed against the hole in the air chamber wall by the spring, and fuel leakage can be prevented. However, when the diaphragm is broken, the same fuel pressure as that of the fuel chamber is applied to the air chamber, and there is a limit to the sealing by the urging force of the spring. For this reason, even if rubber packing or the like is interposed between the head of the screw and the hole in the wall of the air chamber, fuel having a fuel pressure may leak.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a pulsation damper which solves the above-mentioned problems of the prior art and which can prevent a fuel having a fuel pressure from leaking when a diaphragm is abnormal with a simple configuration.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the pulsation damper of the present invention has a diaphragm provided between a fuel chamber communicating with a fuel pipe and an atmosphere opening chamber communicating with the atmosphere through a hole. Reduce. In such a pulsation damper, a moving plug is provided in the hole, and when the diaphragm is abnormal, the moving plug moves to the outside of the open-to-atmosphere chamber to seal the hole.
[0008]
As a result, the hole can be sealed using the pressure itself from the fuel chamber, and fuel leakage can be prevented. The movable tap preferably has a pressure receiving surface on the diaphragm side and a sealing surface between the wall and the wall of the hole, and is preferably inserted into the hole so as to be able to advance and retreat. In addition, by providing a stopper that regulates the movement of the moving tap into the open-to-air chamber, the gap between the moving tap and the wall of the hole does not expand beyond a certain level. Can be generated. Thereby, the movable tap can be moved to the outside of the open-to-atmosphere chamber.
[0009]
In the above pulsation damper, it is preferable that one end of the moving tap is moved to a position that can be visually recognized from outside the open-to-atmosphere at least when the diaphragm is abnormal. Thereby, the abnormality of the diaphragm can be recognized without disassembling the pulsation damper. When the diaphragm is in a position that can be visually recognized from outside the open-to-air chamber not only when the diaphragm is abnormal but also when the diaphragm is normal, the positional relationship between the wall surface of the open-to-air chamber and the movable plug (when the movable plug protrudes from the hole, the protrusion amount) ) Makes it possible to distinguish between a normal state and an abnormal state.
[0010]
In the above pulsation damper, it is preferable that the movable tap has a mark for distinguishing a normal state and an abnormal state of the diaphragm based on a positional relationship with a wall surface of the open-to-air chamber. Thereby, the abnormality of the diaphragm can be easily recognized. As a mark, for example, a convex portion, preferably a flange portion is formed near the end of the moving stopper.
[0011]
In the above pulsation damper, it is preferable that the moving tap has a flat sealing surface facing the outside of the open air chamber or a tapered sealing surface whose diameter is reduced toward the outside of the open air chamber. Thereby, the hole on the wall surface of the air release chamber can be sealed simply by moving the movable stopper outward of the air release chamber.
[0012]
In the pulsation damper, it is preferable that a sealing surface complementary to the sealing surface of the moving tap is provided on a wall surface of the open-to-air chamber. Thereby, the hole can be reliably sealed by the moving stopper. For example, if the sealing surface of the moving tap is flat, a flat sealing surface is provided on the wall surface (inside or around the hole) of the atmosphere opening chamber. Is provided with a sealing surface having a key-like tapered surface on the wall surface.
[0013]
In the pulsation damper, the hole of the open-to-air chamber has a step portion having a smaller diameter than the surroundings, and the movable stopper has a larger diameter than the step portion of the hole, and the diaphragm has a larger diameter than the step when the diaphragm is normal. It is desirable to have at least one or more protrusions disposed inside the open-to-air chamber. In addition, it is preferable that the convex portion disposed on the inside of the open-to-air chamber moves through the step portion to the outside of the open-to-air chamber when the diaphragm is abnormal. When the diaphragm is normal, the movement of the moving tap to the outside of the open chamber is restricted by the convex portion disposed on the inner side of the open chamber from the step portion, thereby preventing the moving tap from sealing the hole. When the diaphragm is abnormal, the movable plug moves through the step portion to the outside of the open-to-atmosphere chamber, so that after the movable plug closes the hole due to the pressure from the fuel chamber, the return to the normal position is restricted. Desirably, the convex portion or the entire movable stopper disposed inside the open-to-air chamber is formed of an elastic material such as rubber or resin.
[0014]
In the pulsation damper, the movable stopper is at least one or more different from the convex portion disposed on the inside of the open-to-air room, which is disposed at a position outside the open-to-air room from the step of the hole when the diaphragm is normal. It is preferable that the convex portion disposed at a position outside the open-to-atmosphere chamber has a larger diameter than the step portion. This restricts the displacement of the moving stopper when the diaphragm is normal. Further, when one or both of the protrusions arranged inside or outside the open-to-air chamber move to a position that can be visually recognized from the outside of the open-to-air chamber when the diaphragm is abnormal, these protrusions may be used. Can be used as a mark for distinguishing between a normal state and an abnormal state based on the positional relationship with the wall surface. In addition, when only the convex portion arranged at the position outside the open-to-air room is visible at normal time, and when both the convex portions arranged inside and outside of the open-to-air room are visible at the time of abnormality, the visible convex portion The numbers make it easier to distinguish between normal and abnormal.
[0015]
Another pulsation damper of the present invention is a pulsation damper that reduces fuel pressure pulsation of the fuel pipe by a diaphragm provided between a fuel chamber communicating with a fuel pipe and an atmosphere opening chamber communicating with the atmosphere through a hole. The hole is formed by an elastic tubular member communicating inside and outside the open-to-air chamber, and is configured so that a part of the hole is crushed when the pressure in the open-to-air chamber increases.
[0016]
Thus, with a simple configuration, the hole can be sealed using the pressure itself from the fuel chamber, and fuel leakage can be prevented. The elastic tubular member is made of, for example, rubber or resin. The collapse of the hole is due to, for example, a pressure loss generated in the hole.
[0017]
In this pulsation damper, it is preferable that an end of the elastic tubular member on the side open to the atmosphere has a tapered surface whose diameter becomes smaller toward the outermost end. Thereby, the tip of the elastic tubular member is deformed by pressure and the hole is easily crushed, so that fuel leakage can be effectively prevented.
[0018]
Further, in this pulsation damper, it is preferable that the elastic tubular member has a convex portion having a diameter larger than the vicinity of the wall surface of the open air chamber in the open air chamber portion of the elastic tubular member. Thereby, even if pressure is applied from the fuel chamber side, the elastic tubular member is prevented from coming outside the open-to-atmosphere chamber. The end of the elastic tubular member on the side of the open air chamber has, for example, an abacus top shape. When the elastic tubular member moves to the outside of the open-to-atmosphere chamber due to the pressure from the fuel chamber, the hole of the elastic tubular member can be closed by pressing the top portion of the abacus against the wall surface of the open-to-atmosphere chamber.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0020]
<1. Configuration of First Embodiment>
FIG. 1 is a schematic cross-sectional view showing the internal configuration of the head of the pulsation damper according to the first embodiment of the present invention. The pulsation damper 1 includes a fuel chamber 2 communicating with a fuel pipe (not shown), and an atmosphere opening chamber 4 communicating with the atmosphere. The fuel chamber 2 and the open-to-atmosphere chamber 4 are disposed adjacent to each other, and a diaphragm 3 is provided between them. A hole 5 for communicating with the atmosphere is formed in the wall surface of the open-to-air chamber 4, and a moving stopper 6 is inserted into the hole 5.
[0021]
Since the fuel pipe communicating with the fuel chamber 2 is connected to a fuel pump and an injector, a fuel pressure pulsation occurs in the fuel pipe, and this is also transmitted to the fuel chamber 2.
[0022]
The diaphragm 3 is made of an elastic film of rubber or the like, and the periphery thereof is fixed between the fuel chamber 2 and the open-to-atmosphere chamber 4. As a result, the diaphragm 3 separates the fuel chamber 2 from the open-to-atmosphere chamber 4 and shuts off the flow of fluid when the diaphragm is normal. One end of a spring 7 is fixed to the diaphragm 3, and the other end of the spring 7 is fixed to a wall surface of the open-to-atmosphere chamber 4.
[0023]
The moving stopper 6 is inserted so as to be able to move forward and backward within a certain movable range in the hole 5, but when the diaphragm is normal, a gap is formed between the wall surface of the hole 5 and the moving stopper 6, so that the moving stopper 6 is open to the atmosphere. The chamber 4 has free communication with the atmosphere. In the illustrated example, the open-to-air chamber 4 is disposed above the fuel chamber 2 and the hole 5 is disposed at the upper end of the open-to-air chamber 4. It is not always necessary to be located above and below the arrangement, and a hole 5 may be provided beside the open-to-atmosphere chamber 4.
[0024]
The moving stopper 6 has a pressure receiving surface 64 on the lower side of the drawing, that is, on the diaphragm 3 side, and has a sealing surface 63 on the wall surface side of the atmosphere opening chamber 4 therefrom. The shape of the sealing surface 63 may be a conical tapered surface whose diameter is reduced toward the outside of the atmosphere opening chamber 4 as shown in the figure, or may be a plane shape facing the outside of the atmosphere opening chamber 4.
[0025]
In addition, the moving stopper 6 is formed with a flange-shaped protrusion 61 and a protrusion 62 having a diameter larger than that of the periphery. The moving stopper 6, especially the portion of the convex portion 61, is formed of an elastic material such as rubber or resin.
[0026]
A sealing surface 43 having a shape to which the sealing surface 63 can be joined is formed on the wall surface of the open-to-atmosphere chamber 4. In particular, it is desirable that the sealing surface 63 and the sealing surface 43 have mutually complementary shapes such that they have a male-female relationship.
[0027]
In the hole 5 of the open-to-atmosphere chamber 4, a step portion 51 having a smaller diameter than the surroundings is formed. When the diaphragm is normal, the moving stopper 6 is arranged between the convex portion 61 and the convex portion 62 such that the step portion 51 is located. That is, when the diaphragm is normal, the convex portion 61 is disposed at a position closer to the inside of the open air chamber than the step portion, and the convex portion 62 is disposed at a position outside the open air chamber from the step portion of the hole. In this state, as described above, a sufficient gap is formed between the seal surface 63 and the seal surface 43. Since the convex portion 61 and the convex portion 62 have a larger diameter than the step portion 51, the movement range is restricted to a position sandwiching the step portion 51.
[0028]
That is, since the movable range of the moving stopper 6 downward in the figure is regulated by the convex portion 62, the gap between the hole 5 and the moving stopper 6 is prevented from expanding beyond a certain value. The stopper structure for restricting the downward movement of the moving stopper 6 is not limited to this, and for example, a separate pressing member may be provided in the atmosphere opening chamber 4 or the like.
[0029]
The upward movement of the movable tap 6 in the figure is first restricted by the convex portion 61. However, since the moving stopper 6 or the convex portion 61 of the present embodiment is formed of an elastic material, when a certain force or more is applied, the convex portion 61 is elastically deformed and passes through the step portion 51. You can also do it.
[0030]
In addition, it is desirable that the convex portion 61 and the convex portion 62 be formed at a position outside the open-to-atmosphere chamber 4 with respect to the sealing surface 63. The step portion 51 is preferably formed at a position outside the open-to-atmosphere chamber 4 with respect to the sealing surface 43, and more preferably at the outermost position of the hole 5 as shown in the figure.
[0031]
Further, in the present embodiment, the horizontal cross-sectional shape of the moving stopper 6 and the hole 5 is circular, but may be other shapes. For example, the convex portion 61 or the convex portion 62 of the moving stopper 6 may have a shape other than the flange shape as long as the convex portion that catches on the step 51 is formed. Further, a plurality of convex portions 61 and convex portions 62 may be provided respectively. Also, when the sealing surface 63 is formed into a tapered surface shape, the sealing surface 63 is not limited to a conical tapered surface, but may have another shape.
<2. Operation of First Embodiment>
In the above configuration, the diaphragm 3 vibrates due to the fuel pressure pulsation in the fuel chamber 2, and air can freely enter and exit through the hole 5 of the open-to-atmosphere chamber 4 when the diaphragm is normal. The spring 7 functions to suppress the vibration of the diaphragm 3 due to the fuel pressure pulsation. Thereby, the pulsation damper 1 can reduce the fuel pressure pulsation of the fuel pipe.
[0032]
Next, with reference to FIG. 2, an operation at the time of abnormality such as breakage of the diaphragm 3 will be described. FIG. 2 is a schematic sectional view showing a state of the pulsation damper of FIG. 1 when the diaphragm is abnormal. When the diaphragm 3 is broken, the fuel in the fuel chamber 2 having a fuel pressure flows into the open-to-atmosphere chamber 4. As a result, the pressure in the open-to-atmosphere chamber 4 increases, and the pressure also acts on the pressure-receiving surface 64 of the moving tap 6. On the other hand, since the air in the open-to-air chamber 4 and the inflowing fuel try to flow out of the open-to-air chamber 4 through the gap between the hole 5 and the moving stopper 6, a pressure loss occurs in the hole 5. . Due to the difference between the pressure applied to the pressure receiving surface 64 and the pressure in the hole 5 reduced by the pressure loss, the moving stopper 6 receives a force upward in the figure (outside the open-to-atmosphere chamber).
[0033]
When the moving stopper 6 is moved upward in the figure by receiving a sufficient force, the sealing surface 63 is joined to the sealing surface 43, and the elastic convex portion 61 passes through the step 51 and is outside the atmosphere opening chamber 4 from the step 51. Go to
[0034]
With the above operation, the moving stopper 6 is pressed against the wall surface of the open-to-atmosphere chamber 4 and the hole 5 is sealed with the force of the fuel pressure itself as the sealing force. Can withstand enough. Further, after the convex portion 61 has climbed over the step 51, the movement of the movable stopper 6 to the lower side in the drawing is restricted by the step 51. It is unlikely that a return force is generated such that the protrusion 61 passes through the step 51 again and returns downward, so that fuel leakage can be sufficiently prevented.
[0035]
Further, in the present embodiment, at least when the diaphragm is abnormal, one end of the moving stopper 6 moves to a position where the moving stopper 6 can be visually recognized from outside the open-to-atmosphere chamber 4. Thereby, the abnormality of the diaphragm can be visually confirmed. In particular, since the second convex portion 62 moves to a position that can be visually recognized from outside the open-to-atmosphere chamber 4, the second convex portion 62 serves as a mark, and an abnormality in the diaphragm can be easily confirmed.
[0036]
Further, as shown in the figure, the second convex portion 62 is disposed at a position where the second convex portion 62 can be visually recognized from the outside of the atmosphere opening chamber 4 even when the diaphragm is normal, and the second convex portion 62 projects further from the wall surface of the atmosphere opening chamber 4 when the diaphragm is abnormal. Therefore, the normal state and the abnormal state can be determined based on the difference in the amount of protrusion of the movable plug 6. In addition, the second convex portion 62 is arranged at a position where the second convex portion 62 can be visually recognized from the outside of the open-to-air chamber 4 in a normal state. Is desirable. Thus, it is possible to easily determine the normal state and the abnormal state based on the number of visible protrusions (marks). In order to make the protrusion 61 visible from the outside at the time of an abnormality, it is desirable that the step 51 is formed at the outermost position of the hole 5.
[0037]
In the case where the protrusions 61 and 62 are provided with separate marks without also serving as the marks, the marks need not be the protrusions and may be visible as long as they are visible.
<3. Configuration of Second Embodiment>
FIG. 3 is a schematic cross-sectional view showing the internal configuration of the head of the pulsation damper according to the second embodiment of the present invention. The pulsation damper 10 according to the second embodiment includes a fuel chamber 20 communicating with a fuel pipe (not shown) and an atmosphere opening chamber 40 communicating with the atmosphere, and a diaphragm 30 is provided therebetween. . One end of a spring 70 is fixed to the diaphragm 30, and the other end of the spring 70 is fixed to a wall surface of the open-to-atmosphere chamber 40. The configurations and operations of the fuel chamber 20, the diaphragm 30, the open-to-atmosphere chamber 40, and the spring 70 are substantially the same as those of the above-described first embodiment having the same names, and a description thereof will be omitted.
[0038]
A hole 50 is formed in the wall surface of the open-to-atmosphere chamber 40, and an elastic tubular member 80 is inserted into the hole 50. The outer diameter of the elastic tubular member 80 is substantially the same as the inner diameter of the hole 50, and does not normally move against the wall surface of the hole 50 due to a frictional force or the like.
[0039]
The elastic tubular member 80 has a hole 85 penetrating in the longitudinal direction, and enables communication with the atmosphere in the atmosphere open chamber 40 when the diaphragm is normal. At the end of the elastic tubular member 80 inside the open air chamber 40, a convex portion 87 having a diameter larger than that of the hole 50 is formed by an upper tapered surface 88, and further, the diameter is reduced by a lower tapered surface 86. In other words, it has the shape of a soroban frame. The end of the elastic tubular member 80 has a minimum diameter, and the hole 85 is open here. The elastic tubular member 80 is preferably made of a soft material such as a soft rubber or a soft resin, and it is particularly desirable that the tip portion is made of such a material.
<4. Operation of Second Embodiment>
FIG. 4 is a schematic sectional view showing a state of the pulsation damper of FIG. 3 when the diaphragm is abnormal. When the diaphragm 30 breaks, the fuel in the fuel chamber 20 having a fuel pressure flows into the open-to-atmosphere chamber 40. As a result, the pressure in the open-to-atmosphere chamber 40 increases, and the pressure also acts on the lower tapered surface 86 of the elastic tubular member 80. On the other hand, since the air in the open-to-air chamber 40 and the inflowing fuel try to flow out of the open-to-air chamber 40 through the hole 85 of the elastic tubular member 80, a pressure loss occurs in the hole 85. Due to the difference between the pressure applied to the lower tapered surface 86 and the pressure in the hole 85 reduced by the pressure loss, the inner end of the elastic tubular member 80 inside the open air chamber 40 receives a pressing force in the direction to contract the hole 85.
[0040]
When the inner end of the elastic tubular member 80 is elastically deformed by receiving a sufficient pressing force, the end of the hole 85 is crushed, and the flow of the fluid to the outside of the open air chamber 40 is blocked.
[0041]
By the above operation, the end of the hole 85 is crushed and sealed by using the force of the fuel pressure itself as a sealing force, so that the fuel pressure can be sufficiently endured. Further, since the upper tapered surface 88 and the convex portion 87 formed by the upper tapered surface 88 are formed, the convex portion 87 functions as a stopper even when the elastic tubular member 80 moves to the outside of the atmosphere opening chamber 40, and the elastic tubular member 80 is opened to the atmosphere. Departure from the chamber 40 is prevented. In addition, since the inner end of the elastic tubular member 80 inside the air opening chamber 40 is reduced in diameter by the lower tapered surface 86, the hole 85 is easily crushed by the elastic deformation of the end.
<5. Modification of Operation of Second Embodiment>
In the operation of the second embodiment, an example in which the elastic tubular member 80 does not move with respect to the hole 50 of the open-to-atmosphere chamber 40 has been described. However, a different operation may be performed. That is, due to the difference between the fuel pressure applied to the inside of the open-to-air chamber 40 and the atmospheric pressure outside the open-to-air chamber 40 when the diaphragm is abnormal, the elastic tubular member 80 is moved upward in FIG. The configuration is as follows. The convex portion 87 of the elastic tubular member 80 has an upper tapered surface 88 whose diameter is reduced upward in the figure. Accordingly, when the elastic tubular member 80 moves upward in the drawing, the upper tapered surface 88 receives a reaction force from the wall surface of the hole 50 in an attempt to bite into the hole 50 of the open-to-atmosphere chamber 40.
[0042]
When the upper tapered surface 88 of the elastic tubular member 80 is elastically deformed by receiving a sufficient reaction force from the wall surface of the hole 50, the end of the hole 85 is crushed, and the flow of fluid to the outside of the open-to-atmosphere chamber 40 is blocked. .
[0043]
Even with the above operation, the end of the hole 85 is crushed and sealed using the force of the fuel pressure itself as the sealing force, so that the fuel pressure can be sufficiently endured. The configuration for moving the elastic tubular member 80 upward in FIG. 3 is similar to that of the first embodiment except that the material or the surface treatment method is selected so that the frictional force between the surface of the elastic tubular member 80 and the wall surface of the hole 50 is reduced. What is necessary is just to employ | adopt the structure itself of 2nd Embodiment. Therefore, the sealing force can be increased in combination with the elastic deformation due to the pressure loss in the hole 85 described with reference to FIG.
[0044]
When the elastic tubular member 80 is moved upward in the figure when the diaphragm is abnormal, as described in the first embodiment, at least at one time when the diaphragm is abnormal, one end of the elastic tubular member 80 is moved from outside the atmosphere opening chamber 40. Move to a visible position. Thereby, the abnormality of the diaphragm can be visually confirmed. In particular, by providing a mark (not shown) on the elastic tubular member 80, abnormality of the diaphragm can be easily confirmed.
[0045]
Further, as shown in the figure, the elastic tubular member 80 is arranged at a position where the elastic tubular member 80 can be visually recognized from the outside of the atmosphere opening chamber 40 even when the diaphragm is normal, and the elastic tubular member 80 projects further from the wall surface of the atmosphere opening chamber 40 when the diaphragm is abnormal. Therefore, the normal state and the abnormal state can be determined based on the difference in the amount of protrusion of the elastic tubular member 80. Further, the number of marks visible from outside may be different between the normal state and the abnormal state of the diaphragm.
<6. Example of arrangement>
FIG. 5 is a perspective view showing a specific example in which the pulsation damper of the present invention is arranged in a fuel system, and FIG. 6 is a perspective view showing an example in which the fuel system is mounted on a passenger car. The fuel system of the vehicle body 9 is connected from a fuel tank 91 to an injector 95 via a fuel pump 92, a fuel pipe 93, and a fuel delivery pipe 94. The fuel in the fuel tank 91 is pressurized by a fuel pump 92 and supplied to an injector 95 through a fuel pipe 93 and a fuel delivery pipe 94. The injector 95 opens and closes in synchronization with the engine rotation, and sprays and supplies fuel to an intake port (not shown) of the engine. The pulsation damper 1 or 10 of the above embodiment is provided in the fuel delivery pipe 94 to prevent fuel pressure pulsation in the fuel pipe.
[0046]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a pulsation damper that can prevent fuel having a fuel pressure from leaking when a diaphragm is abnormal with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an internal configuration of a head of a pulsation damper according to a first embodiment of the present invention.
FIG. 2 is a schematic sectional view showing a state of the pulsation damper of FIG. 1 when a diaphragm is abnormal.
FIG. 3 is a schematic sectional view showing an internal configuration of a head of a pulsation damper according to a second embodiment of the present invention.
FIG. 4 is a schematic sectional view showing a state of the pulsation damper of FIG. 3 when a diaphragm is abnormal.
FIG. 5 is a perspective view showing a specific example in which the pulsation damper of the present invention is disposed in a fuel system.
FIG. 6 is a perspective view showing an example in which the fuel system is mounted on a passenger car.
[Explanation of symbols]
1, 10 Pulsation damper 2, 20 Fuel chamber 3, 30 Diaphragm 4, 40 Air release chamber 43 Sealing surface (of air release chamber) 5 Hole 51 (of air release chamber) Step section 6 Moving tap 61 (of moving tap) The convex portion 62 disposed at a position on the inner side of the open-to-air room The convex portion 63 disposed at a position outside the open-to-air room (of the moving plug) The sealing surface 80 (of the moving plug) Elastic tubular member 85 (of the elastic tubular member) ) Hole 86 Lower taper surface 87 (of elastic tubular member) Convex (of elastic tubular member)

Claims (10)

A pulsation damper that reduces a fuel pressure pulsation of the fuel pipe by a diaphragm provided between a fuel chamber communicating with the fuel pipe and an atmosphere opening chamber communicating with the atmosphere through a hole,
A pulsation damper, wherein a moving stopper is provided in the hole, and when the diaphragm is abnormal, the moving stopper moves outside the open-to-atmosphere chamber to seal the hole. In claim 1,
A pulsation damper, wherein one end of the movable tap moves to a position that can be visually recognized from outside the open-to-atmosphere at least when the diaphragm is abnormal. In claim 2,
The pulsation damper, wherein the movable stopper is provided with a mark for distinguishing a normal state and an abnormal state of the diaphragm based on a positional relationship with a wall surface of the open-to-air chamber. In any one of claims 1 to 3,
The pulsation damper, wherein the moving stopper has a flat sealing surface facing the outside of the open-to-air chamber or a tapered seal surface whose diameter decreases toward the outside of the open-to-air chamber. In claim 4,
A pulsation damper having a sealing surface complementary to the sealing surface of the movable tap on a wall surface of the open-to-atmosphere chamber. In any one of claims 1 to 5,
The hole of the open-to-air chamber has a step that is smaller in diameter than the surroundings,
The moving stopper has a diameter larger than the step portion of the hole, and has at least one or more convex portions disposed closer to the atmosphere open chamber than the step portion when the diaphragm is normal,
A pulsation damper, wherein the projection disposed on the inside of the open-to-air chamber moves out of the open-to-air chamber through the step when the diaphragm is abnormal. In claim 6,
The moving stopper further has at least one or more convex portions, which are different from the convex portions disposed on the inside of the open-to-atmosphere chamber, located at positions outside the open-to-atmosphere chamber from the step portion of the hole when the diaphragm is normal. The projection arranged at a position outside the open-to-atmosphere chamber has a diameter larger than that of the stepped portion. A pulsation damper that reduces a fuel pressure pulsation of the fuel pipe by a diaphragm provided between a fuel chamber communicating with the fuel pipe and an atmosphere opening chamber communicating with the atmosphere through a hole,
The pulsation damper, wherein the hole is formed by an elastic tubular member communicating between the inside and the outside of the open-to-atmosphere chamber, and a part of the hole is collapsed when the pressure in the open-to-atmosphere chamber increases. In claim 8,
A pulsation damper, wherein an end of the elastic tubular member on the side open to the atmosphere has a tapered surface whose diameter becomes smaller toward the end. In claim 8 or claim 9,
A pulsation damper having a convex portion having a diameter larger than the vicinity of the wall surface of the open air chamber of the elastic tubular member in the open air chamber portion of the elastic tubular member.

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