JP2007198522A - Pulsation absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulsation absorber capable of sufficiently absorbing pulsation generated by a small liquid pressure. <P>SOLUTION: This pulsation absorber is provided with a first elastic member 6 elastically deformed by the pressure liquid of liquid in a main body part 2 to which the liquid flows, and absorbs the pulsation of the liquid by elastic deformation of the first elastic member 6. A second elastic member 5 having an elastic modulus lower than the first elastic member 6 is provided in the main body part 2, and the second elastic member 5 is elastically deformed by the liquid pressure of the liquid, and absorbs the pulsation of the liquid in cooperation with the first elastic member 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pulsation absorbing device for absorbing pulsation of liquid flowing in a pipe.

2. Description of the Related Art Conventionally, for example, a hydraulic clutch actuating device for a vehicle is provided with a pulsation absorbing device for absorbing pulsation of liquid generated in a hydraulic circuit due to engine vibration or the like. This pulsation absorbing device is provided with a plate-like member and a piston member that contacts the plate-like member with a certain area. This plate-like member is pressed through a piston member that slides by hydraulic pressure, and elastically deforms like a leaf spring so that the hydraulic pressure in the hydraulic circuit is kept constant and the pulsation of the liquid is absorbed. (For example, refer to Patent Document 1).
JP-A-8-75080

  In a hydraulic clutch operating device for a vehicle, for example, when a booster such as an air booster is used, the hydraulic pressure required for clutch operation is reduced. In this case, the pulsation absorbing device needs to be able to sufficiently absorb the pulsation generated when the hydraulic pressure is small. Therefore, it is preferable that the elastic coefficient of the plate-like member is made small so that the plate-like member can be largely displaced within the elastic range. However, some of the pulsations described above are caused by a sudden large hydraulic pressure, such as when the air booster leaks air. When such a large hydraulic pressure acts on a plate-like member having a small elastic coefficient, the pressing force due to the hydraulic pressure may exceed the elastic range of the plate-like member, and the plate-like member may be plastically deformed. is there. Therefore, the elastic coefficient of the plate-like member needs to be determined within a range where the plate-like member is not plastically deformed, and the pulsation generated when the hydraulic pressure is small cannot be sufficiently absorbed by the plate-like member. . Further, the amount of liquid lost increases due to excessive deformation of the plate-like member, and there is a possibility that the amount of liquid necessary for clutch operation cannot be obtained.

  This invention is made | formed in view of the situation mentioned above, and aims at providing the pulsation absorption apparatus which can fully absorb the pulsation which arose by the small hydraulic pressure.

In the present invention, in the pulsation absorbing device that includes a first elastic member that is elastically deformed by the liquid pressure of the liquid in the main body portion into which the liquid flows, and that absorbs the pulsation of the liquid by elastically deforming the first elastic member, A second elastic member having an elastic coefficient smaller than that of the first elastic member is provided in the main body, and the second elastic member is elastically deformed by the liquid pressure of the liquid and cooperates with the first elastic member. It absorbs the pulsation of the liquid.
According to this configuration, even when a small hydraulic pressure acts, the displacement amount can be increased by the cooperation of the first elastic member and the second elastic member.

In this case, the second elastic member is elastically deformed in cooperation with the first elastic member when the pressing force due to the hydraulic pressure is less than or equal to a predetermined value, and when the pressing force due to the hydraulic pressure is greater than the predetermined value, The second elastic member can be formed to be elastically deformed by being crushed to a contact height that does not cause elastic deformation.
According to this configuration, when the pressing force is less than or equal to the predetermined value, the elastic coefficient of the pulsation absorbing device can be reduced to increase the displacement with respect to the pressing force, while when the pressing force is greater than the predetermined value, the pulsation The elastic modulus as the absorber can be increased.

Further, the second elastic member is formed of a rubber member, and a gap is provided between a pressed surface on which the rubber member is pressed by receiving a hydraulic pressure and a pressing surface of the rubber member in contact with the pressed surface. You may do it.
According to this configuration, the elastic member can be more easily crushed by providing the gap. Further, the ease of crushing the rubber member can be adjusted by the size of the gap.

Furthermore, the first elastic member and the second elastic member may be arranged side by side with respect to one direction in which a pressing force due to hydraulic pressure acts.
According to this configuration, the pulsation absorbing device can be reduced in size by arranging the first elastic member and the second elastic member on the main body.

Further, the first elastic member and the second elastic member may be adjacent to each other.
According to this configuration, the pulsation absorbing device can be further downsized.

On the other hand, the second elastic member may be pressed through a piston that is slidably attached to one direction in which hydraulic pressure acts.
According to this configuration, it is possible to prevent the inflowing liquid from directly contacting the second elastic member.

  According to the present invention, by providing the second elastic member having a smaller elastic coefficient than the first elastic member in the main body, the second elastic member is elastically deformed by the liquid pressure of the liquid, and the first elastic member It can work together to absorb fluid pulsation. Thereby, the pulsation caused by a small hydraulic pressure can be sufficiently absorbed by reducing the elastic coefficient of the pulsation absorbing device as a whole and increasing the displacement.

  Further, the second elastic member is formed so that the first elastic member and the second elastic member cooperate and elastically deform when the pressing force by the hydraulic pressure is a predetermined value or less. When the pressure is less than or equal to a predetermined value, the second elastic member is mainly bent, so that the elastic coefficient of the pulsation absorbing device as a whole can be reduced and the amount of displacement can be increased. Therefore, the pulsation caused by the small hydraulic pressure can be sufficiently absorbed. On the other hand, the second elastic member is formed such that when the pressing force by the hydraulic pressure is larger than a predetermined value, the second elastic member is not elastically deformed and the first elastic member is elastically deformed. When the pressing force is larger than the predetermined value, only the first elastic member bends, so that the amount of displacement as the pulsation absorbing device can be reduced. Therefore, by increasing the elastic coefficient of the second elastic member, the second elastic member will not be plastically deformed even when a large hydraulic pressure is applied. Thereby, for example, when used for preventing pulsation of the clutch fluid, pulsation caused by a small fluid pressure can be absorbed. As a result, vibration transmitted to the driver's foot due to pulsation can be eliminated.

In addition, a pulsation absorbing device that can absorb pulsation due to a small hydraulic pressure by selecting and using the elastic coefficient of the second elastic member by collapsing the second elastic member to a contact height that does not cause elastic deformation. It can be easily configured.
Furthermore, the rubber member can be crushed with a small hydraulic pressure by forming the second elastic member with a rubber member and providing a gap between the pressed surface and the pressing surface of the rubber member.
Further, the first elastic member and the second elastic member are arranged side by side with respect to one direction in which the pressing force by the hydraulic pressure acts, so that the main body portion of the pulsation absorbing device is arranged in a small space. The pulsation absorbing device can be reduced in size.

  On the other hand, when the elastic member is pressed through the piston, the liquid can be prevented from directly contacting the elastic member. Thereby, it is possible to prevent the liquid from leaking from the pulsation absorbing device due to the deformation of the elastic member.

Hereinafter, a pulsation absorbing device according to an embodiment of the present invention will be described with reference to the drawings. Fig.1 (a) and FIG.1 (b) are the schematic diagrams of the pulsation absorber which concerns on embodiment of this invention. Note that the vertical direction used in the following description indicates the direction in the state of FIG.
As shown in FIG. 1, the pulsation absorbing device 1 includes a hollow main body 2 that forms the outside thereof, a piston 3 that is slidably assembled in the hollow shape of the main body 2 in the vertical direction, A coiled spring 4 for biasing the piston 3 downward on the upper side of the piston 3, a reaction rubber (second elastic member) 5 provided on the lower side of the piston 3, and a lower side of the reaction rubber 5 The damper plate (first elastic member) 6 is provided.

As shown in FIGS. 1 (a) and 1 (b), the main body 2 is formed in a substantially cylindrical shape extending along the vertical axis, and has a communication hole 21 communicating from the upper end surface to the lower end surface. Have. The communication hole 21 has a liquid hole 21a formed with a substantially constant diameter downward from the opening 22 on the upper end surface, and a diameter substantially equal to the diameter of the piston 3 downward from the lower end of the liquid hole 21a. And a damper mounting hole having a diameter larger than the diameters of the reaction rubber 5 and the damper plate 6, etc., communicated from the lower end of the piston sliding hole 21 b to the opening 23 on the lower end surface of the main body 2. 21c.
As shown in FIG. 1 (b), two steps are formed on the outer peripheral surface of the main body 2, and this outer peripheral surface has three upper peripheral portions 2a, a central outer peripheral portion 2b, and a lower outer peripheral portion 2c. Consists of parts. The upper outer peripheral portion 2a has a shape whose outer diameter is smaller than the outer diameters of the central outer peripheral portion 2b and the lower outer peripheral portion 2c, and a male screw 24 is processed on the outer peripheral surface. The lower outer peripheral portion 2c is formed in a hexagonal shape in plan view as shown in FIG.

As shown in FIG. 1B, the piston 3 includes a columnar piston main body portion 3a that slides on the peripheral surface of the piston sliding hole 21b, and a spring receiving portion 3b that is positioned above the piston main body portion 3a. Are integrally formed.
The lower end surface of the piston body 3 a forms a horizontal plane, and the entire surface of this plane is in contact with the reaction rubber 5.
The spring receiving portion 3b is formed with a diameter smaller than the outer diameter of the piston main body portion 3a, and a protrusion 25 is formed on the upper portion so as to protrude radially outward from the outer peripheral surface of the spring receiving portion 3b. This protrusion 25 receives the lower end portion of the spring 4 disposed above the spring receiving portion 3b. On the other hand, the upper end of the spring 4 is in contact with the upper wall surface of the piston sliding hole 21b. The spring 4 is attached in a compressed state, and the spring 4 urges the piston 3 downward to press the lower end surface of the piston body 3 a against the reaction rubber 5.
Further, the protrusion 25 functions to hold down the oil seal 26 interposed between the outer peripheral surface of the piston main body 3a and the inner peripheral surface of the piston sliding hole 21b from above. As a result, the liquid flowing in from the liquid hole 21 a does not leak below the oil seal 26.

  FIG. 2 is an enlarged view of the reaction rubber portion of FIG. The reaction rubber 5 has a circular shape having a diameter larger than the diameter of the piston main body 3a in plan view. The reaction rubber 5 is formed in a substantially flat plate shape whose thickness increases toward the central axis. Specifically, the upper surface of the reaction rubber 5 forms a horizontal surface in contact with the lower surface of the piston body 3a as shown in FIGS. 1B and 2, and the lower surface 5a of the reaction rubber 5 It is inclined obliquely downward from the peripheral edge toward the central axis. For example, elastic rubber or the like is used for the reaction rubber 5.

  The damper plate 6 has a circular shape having a diameter larger than the diameter of the reaction rubber 5 in a plan view, and has a substantially constant thickness when viewed from the side as shown in FIG. It has a flat plate shape. The upper surface (pressed surface) 6a of the damper plate 6 is a horizontal surface, and the center portion of the upper surface 6a of the damper plate 6 and the center portion of the lower surface 5a of the reaction rubber 5 are in contact with each other. The gap X is opened without contact. The damper plate 6 functions as a leaf spring having a predetermined elastic coefficient.

Further, as shown in FIGS. 1B and 2, a stop ring 7 that is in contact with the peripheral edge of the lower surface of the damper plate 6 is attached to the lower side of the damper plate 6. The stop ring 7 is provided for providing a predetermined gap on the lower side of the damper plate 6 so that the central portion of the damper plate 6 can be bent downward.
A cap plate 8 that is in contact with the lower end of the stop ring 7 is attached to the lower side of the stop ring 7 as shown in FIGS. The cap plate 8 is for fixing the stop ring 7 at a predetermined position. Further, the cap plate 7 is fixed by a C-type retaining ring 9 from the lower side.

Next, the operation of the pulsation absorbing device according to the embodiment of the present invention will be described in detail with reference to FIG. 1, FIG. 3 (a), FIG. 3 (b) and FIG.
The pulsation absorbing device 1 is configured such that the liquid flowing through the liquid pipe is discharged from the opening 22 on the upper end surface by screwing the male thread portion of the upper outer peripheral portion 2a shown in FIG. It flows into the inside of the main body 2 through the hole 21a. Then, the inflowing liquid presses the piston 3. Thereby, the pulsation of the liquid flowing in the liquid pipe displaces the piston 3 and elastically deforms the reaction rubber 5 and the damper plate 6.

  3A shows the elastic characteristics (elastic coefficient) of the damper plate 6 alone, and FIG. 3B shows the elastic characteristics of the reaction rubber 5 alone. FIG. 4 shows elastic characteristics when the damper plate 6 and the reaction damper 5 are used together. The characteristics shown in FIG. 3A, FIG. 3B, and FIG. 4 show the relationship between the liquid pressure of the liquid flowing in from the liquid hole 21a and the displacement of the piston 3, respectively. In addition, when the pulsation has arisen in the inflowing liquid, the liquid pressure of a liquid will change according to the period of pulsation.

As shown in FIG. 3A, the elastic characteristic 31 of the damper plate 6 alone passes through the origin and is represented by a straight line rising to the right. The elastic characteristic 31 is determined so that the damper plate 6 is displaced so as not to be plastically deformed when a large hydraulic pressure is applied. On the other hand, in this elastic characteristic 31, when a small fluid pressure is applied, the displacement shown on the vertical axis in FIG. 3A is small, so that the pulsation of the fluid may not be sufficiently absorbed.
On the other hand, as shown in FIG. 3B, the elastic characteristic 32 of the reaction rubber 5 alone passes through the origin and is represented by a straight line rising to the right. However, the inclination is larger than the elastic characteristic 31 of the damper plate 6 alone. It has become. That is, the displacement shown on the vertical axis in FIG. 3B is larger than that in FIG.

  In the pulsation absorbing device 1 including the damper plate 6 and the reaction rubber 5 having the characteristics shown in FIGS. 3A and 3B, as shown in FIG. 4, an inflection point is obtained at a predetermined hydraulic pressure. It becomes the characteristic which has 34a. Specifically, when the hydraulic pressure from the origin to the inflection point 34a acts on the pulsation absorbing device 1, the damper plate 6 bends within the elastic range and the reaction rubber 5 is compressed within the elastic range. And bend to fill the gap X shown in FIG. As described above, the reaction rubber 5 and the damper plate 6 cooperate and bend, whereby the elastic characteristic 33 having a larger inclination than the elastic characteristic 31 of the damper plate 6 can be obtained.

  When the fluid pressure at the inflection point 34a acts on the pulsation absorbing device 1, the reaction rubber 5 is completely crushed in the range of the elastic region, and cannot be exerted with any more elastic force. Therefore, when the hydraulic pressure at the inflection point 34 a or higher acts on the pulsation absorbing device 1, the reaction rubber 5 does not exhibit elastic characteristics, so that only the damper plate 6 bends and has the same inclination as the elastic characteristics 31. Become.

  Further, by changing the size of the gap X between the damper plate 6 and the reaction rubber 5, the position of the inflection point 34 a can be arbitrarily changed on the line of the elastic characteristic 33. Specifically, when the vertical dimension Y (see FIG. 2) of the gap X is increased, the reaction rubber 5 is more easily crushed. Therefore, as shown in FIG. 4, the inflection point 34a is shifted to the origin side along the straight line of the elastic characteristic 33 and is changed to the position of the inflection point 34b. In addition, the inclination of the elastic characteristic 31 when a hydraulic pressure larger than the inflection point 34b acts does not change. When the dimension Y is further increased, the inflection point is further shifted to the origin side and can be brought to the position of the inflection point 34c.

  According to the pulsation absorbing device according to the embodiment of the present invention, the reaction rubber 5 is formed so that the damper plate 6 and the reaction rubber 5 are both elastically deformed when the hydraulic pressure is equal to or lower than the inflection point 34a. Thus, the reaction rubber 5 and the damper plate 6 cooperate and bend, whereby the displacement as the pulsation absorbing device 1 can be increased. Therefore, the pulsation caused by the small hydraulic pressure can be sufficiently absorbed. On the other hand, the reaction rubber 5 is designed not to be elastically deformed when the hydraulic pressure is higher than the inflection point 34a. Therefore, only the damper plate 5 bends, so that the displacement as the pulsation absorbing device 1 is reduced. Can be small. Therefore, even if a large hydraulic pressure acts on the damper plate 5, the damper plate 5 is not plastically deformed. Thereby, for example, when used for preventing pulsation of the clutch fluid, the pulsation caused by the small hydraulic pressure can be sufficiently absorbed and the pulsation can be eliminated. it can.

In addition, the reaction rubber 5 can be easily pulsated by selecting and using the elastic coefficient of the reaction rubber 5 by being crushed to a contact height at which the reaction rubber 5 does not cause elastic deformation (the height when the reaction rubber 5 is completely crushed). An absorber can be constructed.
Furthermore, by providing a gap between the upper surface of the damper plate 5 and the pressing surface of the reaction rubber 5, the reaction rubber 5 can be crushed to a close contact height with a small hydraulic pressure.
Furthermore, the reaction rubber 5 is pressed through the piston 3 so that the liquid does not directly contact the reaction rubber 5. Accordingly, the reaction rubber 5 can be prevented from leaking from the pulsation absorbing device due to the reaction rubber 5 being deformed by the hydraulic pressure.

The best mode for carrying out the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made based on the technical idea of the present invention. .
In this embodiment, the reaction rubber 5 and the damper plate 6 are arranged side by side with respect to the direction in which the hydraulic pressure acts. It does not have to be. Further, the reaction rubber 5 and the damper plate 6 may not be adjacent to each other. Also by these, pulsations caused by a small hydraulic pressure can be sufficiently absorbed as in the present embodiment.
In the present embodiment, the rubber reaction rubber 5 is used. However, if it can absorb the pressing force due to the hydraulic pressure and is crushed to the contact height by the predetermined pressing force, the elasticity of the compression spring or the like can be obtained. It can also be comprised with the member which has. Thereby, the effect equivalent to the reaction rubber 5 can be acquired.

1 is a pulsation absorbing device according to an embodiment of the present invention, where (a) is a plan view and (b) is a side cross-sectional view. FIG. 2 is an enlarged side sectional view showing a reaction rubber portion in FIG. It is an elastic characteristic of the pulsation absorber which concerns on embodiment of this invention, Comprising: (a) shows the elastic characteristic of a damper plate single-piece | unit, (b) is a figure which shows the elastic characteristic of a reaction rubber single-piece | unit. It is a figure which is an elastic characteristic of the pulsation absorber which concerns on embodiment of this invention, Comprising: It is a figure which shows an elastic characteristic at the time of using a damper plate and reaction rubber together.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulsation absorber 2 Main-body part 2a Upper outer peripheral part 3 Piston 4 Spring 5 Reaction rubber (2nd elastic member)
5a Underside of reaction rubber 6 Damper plate (first elastic member)
6a Upper surface of damper plate (pressed surface)
7 Stop ring 8 Cap plate 9 C-type retaining ring 21 Communication hole 21a Liquid hole 21b Piston sliding hole 21c Damper mounting hole 22 Upper end surface opening 23 Lower end surface opening 24 Male screw 25 Projection 26 Oil seal 31 Elasticity of damper plate alone Characteristic 32 Elastic property of reaction rubber alone 33 Elastic property of damper plate and reaction rubber 34a, 34b, 34c Inflection point X Clearance

Claims (6)

In the pulsation absorbing device that includes a first elastic member that is elastically deformed by the liquid pressure of the liquid in the main body portion into which the liquid flows, and that absorbs the pulsation of the liquid by elastically deforming the first elastic member,
A second elastic member having an elastic coefficient smaller than that of the first elastic member is provided in the main body, and the second elastic member is elastically deformed by the liquid pressure of the liquid and cooperates with the first elastic member. And a pulsation absorbing device that absorbs the pulsation of the liquid.   The second elastic member is elastically deformed in cooperation with the first elastic member when the pressing force due to hydraulic pressure is less than or equal to a predetermined value, and the second elastic member when the pressing force due to hydraulic pressure is greater than the predetermined value. 2. The pulsation absorbing device according to claim 1, wherein the first elastic member is elastically deformed by being crushed to a contact height that does not cause elastic deformation.   The second elastic member is formed of a rubber member, and a gap is provided between a pressed surface on which the rubber member is pressed by receiving a hydraulic pressure and a pressing surface of the rubber member that is in contact with the pressed surface. The pulsation absorbing device according to claim 1 or 2, wherein   The said 1st elastic member and the said 2nd elastic member are arrange | positioned along with one direction where the pressing force by a hydraulic pressure acts, The any one of Claims 1-3 characterized by the above-mentioned. The pulsation absorbing device according to 1.   The pulsation absorbing device according to claim 4, wherein the first elastic member and the second elastic member are adjacent to each other. The said 2nd elastic member is pressed through the piston slidably attached with respect to one direction on which hydraulic pressure acts, The one of Claims 1-5 characterized by the above-mentioned. The pulsation absorbing device according to 1.

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