JP2008240780A - Pulsation absorption device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent early damage of a sealing material arranged at a liquid pressure chamber side of a pulsation absorption plate in a pulsation absorption device using the pulsation absorption plate such as a metal diaphragm. <P>SOLUTION: The sealing material 80, the metal diaphragm 10 and a support member 70 arranged in a mounting hole 98 are supported on a cylindrical inner peripheral wall 99 formed on the mounting hole 98 from an outer peripheral side. According to this, even when the metal diaphragm 10 receiving the liquid pressure is deflected/deformed, a new void for causing biting of the sealing material 80 between the metal diaphragm 10 and a housing 90 does not occur. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pulsation absorbing device that is provided at an intermediate position of a hydraulic circuit of a clutch system in an automobile, for example, and suppresses pulsation of a working fluid. In particular, the present invention relates to a pulsation absorbing device using a pulsation absorbing plate, which is a flexible plate member, as a medium for suppressing pulsation, and prevents damage to a sealing material disposed on the hydraulic chamber side of the pulsating absorbing plate. It relates to the technology effective above.

A clutch system provided in an automobile includes a master cylinder that generates a hydraulic pressure by a driver's pedal operation, and a slave cylinder that is operated by the hydraulic pressure generated in the master cylinder and intermittently engages the clutch device. A pulsation absorbing device is provided in the middle of the flow path connecting these master cylinder and slave cylinder. The pulsation absorbing device suppresses the pulsation generated by the clutch device and transmitted through the piping, and the pulsation vibrates the pedal to eliminate the unpleasant feeling given to the driver. In such a pulsation absorbing device, a medium using an elastic member such as a rubber spring as a medium for suppressing pulsation (for example, refer to Patent Document 1) and a metal diaphragm as a pulsation absorbing plate (for example, refer to Patent Document 2) ) These media suppress pulsation and at the same time receive the hydraulic pressure of the working fluid. In this respect, the metal diaphragm is less deformed when subjected to hydraulic pressure than the rubber spring. For this reason, a pulsation absorbing device using a pulsation absorbing plate such as a metal diaphragm has an advantage that there is less hydraulic pressure loss than that using an elastic member such as a rubber spring.
Japanese Utility Model Publication No. 62-85732 Japanese Patent Laid-Open No. 2004-278639

  A metal diaphragm of such a pulsation absorbing device is a flat plate member having a uniform thickness disposed in a mounting hole of a housing as shown in, for example, Patent Document 2, and a pressure is applied to the inner side of the mounting hole. A hydraulic chamber that is part of the flow path through which the fluid flows is defined. In this metal diaphragm, the outer peripheral portion of one surface on the hydraulic chamber side is in contact with a step portion formed in the housing, and the outer peripheral portion of the other surface is supported by a ring-shaped support member. This support member has a circular cross section and serves as a fulcrum when the metal diaphragm vibrates. With this structure, the metal diaphragm is sandwiched between the step of the housing and the support member in a direction perpendicular to the surface. An annular sealing material that prevents leakage of the working fluid is disposed on the hydraulic chamber side of the metal diaphragm. This sealing material is disposed on the inner diameter side of the step portion of the housing, and is in close contact with the sealing surface in the mounting hole and the metal diaphragm in a state of being elastically compressed and deformed in the axial direction.

  In such a pulsation absorbing device, when the metal diaphragm is bent with the contact portion with the support member as a fulcrum by the pressure increase of the hydraulic chamber, a gap is generated between the metal diaphragm and the step portion of the housing. At this time, the sealing material located inside the stepped portion receives pressure from the hydraulic chamber and is pressed toward the gap. As a result, the outer peripheral edge of the sealing material may be less likely to enter the gap. After that, when the metal diaphragm returns to its original flat shape, the outer peripheral edge portion of the sealing material is bitten between the metal diaphragm and the stepped portion of the housing (so-called seal). Erosion of the material). By repeating such a phenomenon, the seal material is damaged early.

  An object of the present invention is to provide a technique effective in preventing early damage of a sealing material disposed on a hydraulic pressure chamber side of a pulsation absorbing plate in a pulsation absorbing device using a pulsation absorbing plate such as a metal diaphragm. To do. Other objects of the present invention will become clear from the following description.

  One of the features of the pulsation absorbing device according to the present invention is that each of the members arranged in the mounting hole of the housing is configured to arrange each of the sealing material, the pulsation absorbing plate, and the supporting member arranged from the inner back side toward the opening side. It is in. In the present invention, the sealing material, the pulsation absorbing plate, and the support member are respectively supported from the outer peripheral side by a cylindrical inner peripheral wall formed in the mounting hole of the housing. The cylindrical inner peripheral wall formed in the mounting hole has the same diameter and extends in the axial direction, and supports the sealing material, the pulsation absorbing plate, and the support member inside thereof. A holding member for holding the support member from the opening side is provided on the opening side of the mounting hole with respect to the support member. This holding member prevents the sealing material, the pulsation absorbing plate and the support member arranged in the mounting hole from coming out of the mounting hole.

  In the pulsation absorbing device of the present invention, the pulsation absorbing plate is supported by the sealing material on the outer peripheral portion of one surface on the hydraulic chamber side and supported by the supporting member on the outer peripheral portion of the other surface. And the support member in a direction perpendicular to the surface. According to this configuration, when the pulsation absorbing plate is bent and deformed by increasing the pressure in the hydraulic chamber, no new gap is generated between the pulsation absorbing plate and the housing. Therefore, it is possible to avoid a situation in which the sealing material bites into the gap formed between the pulsation absorbing plate that has been bent and deformed and the housing, and it is possible to prevent early damage to the sealing material due to such biting. In addition, since this pulsation absorbing plate is bent and deformed with the contact portion with the support member as a fulcrum, the sealing material provided so as to sandwich the pulsation absorbing plate between the support member and the pulsation absorbing plate In particular, it will be in contact with the portion with the least amount of deformation. Therefore, the deformation amount of the sealing material can be minimized, and this also prevents early damage to the sealing material.

  The support member in the present invention serves as a fulcrum when the vibration absorbing plate vibrates. For example, a ring-shaped member having a circular cross section can be used. In this case, the support member can be generally composed of a commercially available steel wire. Further, the vibration absorbing plate can be supported by the top of the wire having a circular cross section, and an extremely narrow portion can be used as a fulcrum, and the vibration absorbing plate can be supported with high reactivity. Moreover, in this invention, the cover member which closes an attachment hole can be interposed between the holding member and support member which were distribute | arranged in the attachment hole. In this case, since the lid member can block the vibration absorbing plate from the outside air, the vibration absorbing plate can be isolated from water and dust to prevent corrosion such as rust.

  Further, in the pulsation absorbing device of the present invention, a C-type retaining ring that can be elastically deformed in the expansion / contraction diameter direction can be used as the holding member that holds the support member from the opening side of the mounting hole. The C-type retaining ring is inserted into a circumferentially extending groove formed near the opening in the mounting hole. According to the pulsation absorbing device having such a configuration, after each component is installed in the mounting hole, the holding member is passed through the opening of the mounting hole in a state of being contracted in the diameter reducing direction against the elastic force, and by the elastic force The assembly is completed by inserting the outer peripheral portion of the holding member to be expanded into the groove portion of the mounting hole. Therefore, its assembly is relatively simple. Further, since a commercially available C-type retaining ring can be used, the cost can be reduced.

  Furthermore, in the pulsation absorbing device of the present invention, the sealing material may be a cup seal that is elastically supported between the sealing surface in the mounting hole and the pulsation absorbing plate. The cup seal includes a first lip portion that elastically contacts the sealing surface in the mounting hole, a second lip portion that elastically contacts the pulsation absorbing plate, and rear end portions of the first and second lip portions. And a base portion that contacts the cylindrical inner peripheral wall of the mounting hole. If a cup seal is used as the sealing material, for example, each lip portion has its own elasticity and strength compared to the case where a sealing material is used that obtains a sealing action only by the clamping force between two members, such as an O-ring. Since the sealing action is generated by the pressure from the hydraulic chamber, it can be followed by the bending deformation of the pulsation absorbing plate.

  FIG. 1 is a pulsation absorbing device 100 according to a first embodiment of the present invention, and shows a cross-sectional structure cut in the axial direction. A housing 90 which is a main body of the pulsation absorbing device 100 has a mounting hole 98 for providing the metal diaphragm 10 or the like as a pulsation absorbing plate, and a part of a flow path through which pressure fluid flows inside the mounting hole 98. A hydraulic chamber 94 is formed. The housing 90 includes a first communication port 92 that communicates with the master cylinder 200 and a second communication port 93 that communicates with the slave cylinder 300. The hydraulic chamber 94 is provided so as to communicate between the first and second communication ports 92 and 93. The metal diaphragm (pulsation absorbing plate) 10 provided to partition the hydraulic pressure chamber 94 serves to suppress pulsation generated in the working fluid in the hydraulic pressure chamber 94. The metal diaphragm 10 defines a fluid pressure chamber 94 on one surface 11 and a constant pressure chamber 95 on the other surface 12.

  The metal diaphragm 10 in this embodiment is a flat plate member having a uniform thickness with a thickness of about 0.5 to 1.0 mm. In the metal diaphragm 10, the outer peripheral portion of the one surface 11 on the hydraulic chamber 94 side is supported by the sealing material 80, and the outer peripheral portion of the other surface 12 is supported by the support member 70. As a result, the metal diaphragm 10 is sandwiched between the sealing material 80 and the support member 70 in a direction perpendicular to the surface 11 (12).

  The seal member 80 is elastically supported between the seal surface 97 formed at the step portion of the mounting hole 98 and the metal diaphragm 10, and the metal diaphragm 10 is deformed by receiving fluid pressure and bending toward the constant pressure chamber 95 side. Sometimes, it always has elastic deformation that makes contact with its surface. Such a sealing material 80 prevents leakage of the pressure fluid in the hydraulic chamber 94. In addition, the sealing material in this one embodiment shown in FIG. 1 employs a rectangular cross section without elastic deformation, and shows a state in which it is swollen to the inner peripheral side by elastic deformation.

  The support member 70 disposed on the constant pressure chamber 95 side with respect to the metal diaphragm 10 is a metal ring-shaped member having a circular cross section, and supports the outer peripheral portion of the metal diaphragm 10 in a linear contact over the entire circumference. . Such a support member 70 becomes a fulcrum when the metal diaphragm 10 vibrates.

  In the vicinity of the opening 91 of the mounting hole 98, a holding member 50 for holding the support member 70 with a lid member 60 interposed is provided. The holding member 50 prevents each member such as the metal diaphragm 10 disposed in the attachment hole 98 from coming out of the attachment hole 98. As can be understood from the bottom view of the pulsation absorbing device 100 shown in FIG. 2, the holding member 50 here is a substantially arc-shaped C-side retaining ring that can be elastically deformed in the expansion / contraction diameter direction. It is inserted into a circumferentially extending groove 96 provided near the opening 91. Small holes 52 and 53 for mounting are formed at both ends of the holding member 50, and a tool is inserted into the small holes 52 and 53 to reduce the diameter against the elastic force of the holding member 50 itself. Can do. According to such a holding member 50, after each component member such as the metal diaphragm 10 is arranged in the attachment hole 98, the opening 91 of the attachment hole 98 is formed in a state where the diameter of the holding member 50 is reduced against the elastic force. The assembly is simply completed by inserting the outer peripheral portion 59 of the holding member 50 whose diameter is increased by the elastic force into the groove portion 96.

  The lid member 60 interposed between the support member 70 and the holding member 50 closes the attachment hole 98. By providing the lid member 60, the metal diaphragm 10 can be shielded from the outside air, and the metal diaphragm 10 can be isolated from water and dust to prevent corrosion such as rust.

  Now, the sealing material 80, the metal diaphragm 10 and the support member 70 arranged in order from the inner back to the opening 91 in the mounting hole 98 are supported from the outer peripheral side by a cylindrical inner peripheral wall 99 formed in the mounting hole 98. ing. The cylindrical inner peripheral wall 99 extends with the same diameter from the inner deep seal surface 97 in contact with the sealing material 80 to a position reaching the constant pressure chamber 95. The sealing material 80 and the support member 70 have an outer diameter that is substantially the same as the inner diameter of the cylindrical inner peripheral wall 99 within a range that fits within the cylindrical inner peripheral wall 99. On the other hand, the outer diameter of the metal diaphragm 10 is larger than the inner diameter of the cylindrical inner peripheral wall 99 within a range in which a space required for the bending deformation can be secured so that it can be bent and deformed in the cylindrical inner peripheral wall 99. Also designed to be small. That is, the outer peripheral end portion 19 of the metal diaphragm 10 (the portion positioned on the outer periphery of the support point 17 by the support member 70) contacts the cylindrical inner peripheral wall 99 even when the metal diaphragm 10 is deformed by receiving a hydraulic pressure. By doing so, the bending deformation is not hindered.

  In such a pulsation absorbing device 100, since the metal diaphragm 10 is sandwiched between the sealing material 80 and the support member 70 in the axial direction, even when the metal diaphragm 10 that has been subjected to hydraulic pressure is bent and deformed, the metal diaphragm 10 and There is no new gap between the housing 90 and the sealing material 80 that can be bitten. Further, the seal member 80 is provided so as to sandwich the metal diaphragm 10 with the support member 70 serving as a fulcrum of deformation, so that the seal member 80 contacts a portion with the least deformation amount among the metal diaphragm 10 that is bent and deformed. Is. With this configuration, the pulsation absorbing device 100 prevents the sealing material 80 from being bitten along with the bending deformation of the metal diaphragm 10 and minimizes the deformation amount of the sealing material 80 due to the bending deformation of the metal diaphragm 10. By suppressing to the above, early damage of the sealing material 80 is prevented.

  FIG. 3 shows another embodiment of the present invention, and shows a cross-sectional structure of a pulsation absorbing device 500 according to the second embodiment. The pulsation absorbing device 500 is obtained by replacing the sealing member 80 having a rectangular cross section of the pulsating absorbing device 100 in the first embodiment with a cup seal type sealing material 580. The other components except for the sealing material 580 and the function and effect thereof are basically the same as those of the pulsation absorbing device 100 described above. Therefore, the detailed description here is omitted for the basically same components. The sealing material (cup seal) 580 of the pulsation absorbing device 500 is elastically supported between the sealing surface 97 in the mounting hole 98 and the metal diaphragm (pulsation absorbing plate) 10. The cup seal 580 includes a first lip portion 589 that elastically contacts the sealing surface 97 in the mounting hole 98, a second lip portion 581 that elastically contacts the metal diaphragm 10, and the first lip portion 589. And a base portion 588 that connects the rear end portions of the second lip portion 581 and contacts the cylindrical inner peripheral wall 99 of the mounting hole 98. The cup seal 580 can be followed by the bending deformation of the metal diaphragm 10 because each lip portion 589, 581 generates a sealing action by its own elasticity and pressure from the hydraulic chamber.

  FIG. 4 shows still another embodiment, and shows a cross-sectional structure of a pulsation absorbing device 600 according to the third embodiment. In this pulsation absorbing device 600, a plate 80 is inserted between the sealing material 80 and the metal diaphragm 10 of the pulsation absorbing device 100 in the first embodiment. The other components except for the plate 80 and the operation and effects thereof are basically the same as those of the pulsation absorbing device 100 described above. Therefore, the detailed description here is omitted for the basically same components. As described above, the outer diameter of the metal diaphragm 10 is designed to be smaller than the inner diameter of the cylindrical inner peripheral wall 99 so that the metal diaphragm 10 can be bent and deformed in the cylindrical inner peripheral wall 99. In the pulsation absorbing device 100 in the first embodiment, the outer peripheral edge portion of the sealing material 80 on the metal diaphragm 10 side can be inserted into the radial gap between the outer peripheral edge of the metal diaphragm 10 and the cylindrical inner peripheral wall 99. It has sex. On the other hand, in the pulsation absorbing device 600 provided with the plate 20, the outer diameter of the plate 20 is substantially the same as the inner diameter of the cylindrical inner peripheral wall 99, so that the sealing material 80 can be prevented from being bitten. it can. The plate 20 is made of, for example, a resin material so as not to disturb the pulsation absorbing action of the metal diaphragm 10, and is configured to be thinner and more flexible than the metal diaphragm 10.

It is sectional drawing of the pulsation absorber 100 using the metal diaphragm 10 which is 1st Example of this invention. 3 is a bottom view of the pulsation absorbing device 100. FIG. It is sectional drawing of the pulsation absorber 500 which is 2nd Example of this invention. It is sectional drawing of the pulsation absorber 600 which is the 3rd Example of this invention.

Explanation of symbols

10 Pulsation absorbing plate (metal diaphragm)
50 Holding member (C-type retaining ring)
70 Support member (ring-shaped member)
80 Seal material 90 Housing 94 Hydraulic chamber 100 Pulsation absorber 500 Pulsation absorber 580 Seal material (cup seal)

Claims (3)

A pulsation absorbing device for suppressing pulsation of pressure fluid,
A housing that has a mounting hole that opens outward, and forms a hydraulic chamber that is part of a flow path through which the pressure fluid flows on the inner back side of the mounting hole;
A pulsation absorbing plate that is disposed in the mounting hole so as to partition the hydraulic pressure chamber, and absorbs the pulsation by vibrating due to the pulsation transmitted to the pressure chamber;
A seal that is disposed on the inner side of the mounting hole with respect to the vibration absorbing plate and is elastically supported between the pulsation absorbing plate and a sealing surface in the mounting hole to prevent leakage of pressure fluid in the hydraulic chamber. Material,
A support member that is disposed on the opening side with respect to the pulsation absorbing plate in the mounting hole and serves as a fulcrum when the pulsation absorbing plate vibrates by contacting the outer peripheral portion of the pulsation absorbing plate;
A holding member that is disposed on the opening side with respect to the supporting member and holds the supporting member from the opening side;
In the pulsation absorbing device comprising
Of the members disposed in the mounting hole of the housing, the sealing material, the pulsation absorbing plate, and the support member arranged from the inner back side toward the opening side have the same diameter formed in the mounting hole. A pulsation absorbing device, characterized in that the pulsation absorbing device is supported by a cylindrical inner peripheral wall extending in the axial direction from each outer peripheral side.   The holding member is a C-type retaining ring that is elastically deformable in an expansion / contraction diameter direction and is inserted into a circumferentially extending groove formed near an opening in the mounting hole. The pulsation absorbing device as described.   The seal material is a cup seal that is elastically supported between a seal surface in the mounting hole and the pulsation absorbing plate, and a first lip portion that elastically contacts the seal surface in the mounting hole; A second lip portion that elastically contacts the absorbing plate; and a base portion that connects the rear end portions of the first and second lip portions and contacts the cylindrical inner peripheral wall of the mounting hole. The pulsation absorbing device according to claim 1 or 2.

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