JP2015230022A - Flow rate control mechanism and fluid bearing device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a static pressure fluid bearing device which inhibits unexpected vibrations of a diaphragm.SOLUTION: A flow rate control mechanism 10 controls a flow rate of a fluid pumped by a pump P. The flow rate control mechanism 10 includes: a valve housing 20; and a diaphragm 60 which divides an interior chamber of the valve housing 20 into a discharge chamber 70 and a back pressure chamber 71. An extension member 80, which is connected with the diaphragm 60 and moves relative to the valve housing 20 while following deformation of the diaphragm 60, is disposed extending in a direction perpendicular to a surface of the diaphragm 60. A damping member 95 which inhibits vibrations of the diaphragm 60 is disposed between the valve housing 20 and the extension member 80.

Description

  The present invention relates to a flow rate control mechanism and a hydrodynamic bearing device including the same.

  In the hydrostatic fluid bearing device, one that is configured to control the flow rate of the fluid pumped from the pump by a flow rate control mechanism and supply the fluid to the hydrostatic pocket of the hydrostatic fluid bearing is known. As a flow rate control mechanism, a diaphragm type flow rate control mechanism including a valve rod and a diaphragm that divides an inner chamber of the valve rod into a discharge chamber and a back pressure chamber is known. In the diaphragm type flow control mechanism, the diaphragm is deformed (deflection deformation) according to the pressure difference between the discharge chamber and the back pressure chamber, thereby increasing or decreasing the opening degree of the outlet of the valve rod, thereby supplying the fluid supply flow rate. Is controlling. A hydrostatic bearing device using such a diaphragm flow control mechanism is disclosed in, for example, Patent Document 1.

JP 2012-107744 A

  By the way, in the hydrostatic bearing device using the diaphragm type flow control mechanism, when the diaphragm is suddenly deformed due to disturbance or the like, the pressure in the back pressure chamber fluctuates accordingly. The diaphragm unexpectedly fluctuates due to the fluctuation of the pressure in the back pressure chamber, and such a function is repeated, so that the unexpected vibration of the diaphragm is amplified and the fluid bearing function is deteriorated.

  In view of the above problems, an object of the present invention is to provide a flow rate control mechanism capable of suppressing unexpected vibration of a diaphragm and a hydrodynamic bearing device including the same.

  In order to solve the above problems, a flow rate control mechanism according to a first aspect of the present invention is a flow rate control mechanism that controls a flow rate of a fluid pumped from a pump, and the flow rate control mechanism includes a valve rod, A diaphragm that divides an inner chamber of the valve rod into a discharge chamber and a back pressure chamber, the diaphragm being connected to the diaphragm and moving relative to the valve rod following the deformation of the diaphragm; Is extended in a direction perpendicular to the surface of the diaphragm, and a damping member for suppressing vibration of the diaphragm is disposed between the valve rod and the extending member.

  According to the first aspect of the present invention, when the diaphragm is about to deform rapidly, the movement of the extending member following the deformation of the diaphragm is attenuated by the damping member disposed between the valve rod and the extending member. For this reason, rapid deformation of the diaphragm and unexpected vibration of the diaphragm can be suppressed.

  A flow rate control mechanism according to a second aspect of the present invention is the flow rate control mechanism of the first aspect, wherein the extending member protrudes through the valve rod, and a protruding portion of the extending member has a flange or a recess. On the other hand, the valve flange side is formed with an inner peripheral flange that is opposed to the flange or recess by a predetermined distance in the moving direction of the extending member, and the flange or recess and the inner The attenuating member is disposed in a state of being sandwiched between the peripheral flanges.

  According to the second aspect of the invention, the damping member can be easily disposed between the flange or recess formed in the protruding portion of the extending member and the inner peripheral flange formed on the valve flange side.

  A flow control mechanism according to a third invention is the flow control mechanism of the second invention, wherein the inner peripheral flange is formed on an inner peripheral surface of a fixed cylinder member fixed to the valve rod. Features.

  According to the third invention, the inner peripheral flange can be easily formed on the inner peripheral surface of the fixed cylinder member as compared with the case where the inner peripheral flange is formed on the valve rod.

  A flow rate control mechanism according to a fourth aspect of the present invention is the flow rate control mechanism according to the third aspect of the present invention, wherein the fixed cylinder member is disposed with respect to the valve rod so that the height can be adjusted by a height adjustment mechanism. It is characterized by that.

  According to the fourth aspect of the present invention, the height of the fixed cylinder member is adjusted with respect to the valve rod by the height adjusting mechanism, so that the damping member is appropriately disposed between the inner peripheral flange of the fixed cylinder member and the flange portion of the extending member. It can arrange | position in a state. For example, it is possible to inhibit the diaphragm from being inhibited from being deformed by the damping member, and the damping function of the damping member from being lowered.

  A flow rate control mechanism according to a fifth aspect of the present invention is the flow rate control mechanism of the fourth aspect of the present invention, wherein the height adjusting mechanism is a plurality of fastenings that fasten and fix the fixed cylinder member to the mounting surface of the valve rod. A bolt and an adjusting screw for adjusting the height position of the fixed cylinder member with respect to the mounting surface of the valve rod are provided.

  According to the fifth aspect of the present invention, after adjusting the height position of the fixed cylinder member with the adjusting screw to the mounting surface of the valve rod, the fixed cylinder member is fastened and fixed to the mounting surface of the valve rod with the plurality of fastening bolts. Thus, the fixed cylinder member can be easily adjusted to a desired height position.

  A flow rate control mechanism according to a sixth aspect of the present invention is the flow rate control mechanism according to any one of the first to fifth aspects of the present invention, wherein the damping member has characteristics that the rigidity is lower and the damping property is higher than that of the stretching member. It is characterized by having.

  According to the sixth aspect of the present invention, the rapid deformation of the diaphragm can be satisfactorily suppressed by the damping member having the characteristics that the rigidity is lower than that of the extending member and the damping property is high.

  A fluid dynamic bearing device according to a seventh aspect is characterized in that the fluid whose flow rate is controlled by the flow rate control mechanism according to any one of the first to sixth aspects is supplied to a pocket of the fluid dynamic bearing.

  According to the seventh invention, a stable fluid bearing function can be obtained.

  According to the present invention, unexpected vibration of the diaphragm can be suppressed, and a stable fluid bearing function can be obtained. That is, the rigidity of the fluid bearing can be increased.

It is explanatory drawing which shows the outline of the hydrostatic bearing device which concerns on Example 1 of this invention. It is a longitudinal cross-sectional view which shows the flow control mechanism of a hydrostatic bearing device. It is a longitudinal cross-sectional view which expands and shows the principal part of a flow control mechanism. It is a top view which shows the arrangement | positioning state of the fastening bolt and adjustment screw of a height adjustment mechanism. It is a longitudinal cross-sectional view which shows the state which the pressure of the suppression pocket fell and the diaphragm deform | transformed. It is a longitudinal cross-sectional view which shows the flow control mechanism which concerns on Example 2 of this invention.

  A mode for carrying out the present invention will be described in accordance with an embodiment.

  A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the hydrostatic bearing device is formed in the bearing body 2 of the hydrostatic fluid bearing 1 by controlling the flow rate of the fluid (liquid or gas) pumped from the pump P by the flow rate control mechanism 10. Then, the guide surface 7 of the movable body 6 (rotary body or slide body) is moved and guided in a non-contact state.

  As shown in FIG. 2, the flow rate control mechanism 10 includes a valve rod 20 and a steel plate diaphragm 60 that divides the inner chamber of the valve rod 20 into a discharge chamber 70 and a back pressure chamber 71.

  In the first embodiment, the valve rod 20 includes a first valve rod body 21 and a second valve rod body 41. A stepped recess 21 a having a small diameter on the bottom side and a large diameter on the opening side is formed at the center of the upper surface of the first valve housing 21, and the stepped surface is used as the installation surface 24 of the diaphragm 60. And the discharge chamber 70 is formed in the bottom face side of the step-shaped recessed part 21a, and the opening side of the step-shaped recessed part 21a is used as the fitting recessed part 22. Further, a protrusion 26 is formed on the bottom surface of the stepped recess 21 a of the first valve housing 21, and the protrusion end surface of this protrusion 26 is between the diaphragm 60 installed on the installation surface 24, A valve seat surface 27 that separates the set gap is formed. A fluid outlet 30 is formed in the center of the protrusion 26 so as to penetrate therethrough. In addition, an inlet 31 to which a supply pipe leading to the pump P is connected is formed in a side portion of the first valve housing 21, and a discharge-side inlet hole leading to the discharge chamber 70 is formed on the back side of the inlet 31. 32 and a back pressure side inflow hole 33 communicating with the back pressure chamber 71 are formed in parallel.

  A fitting convex portion 42 that fits into the fitting concave portion 22 is formed at the center of the lower surface of the second valve housing 41. Then, after the diaphragm 60 is installed on the installation surface 24 of the first valve housing 21, the fitting convex portion 42 is fitted to the fitting concave portion 22. Further, a plurality of second valve rod bodies 41 toward the first valve rod body 21 with the lower surface of the peripheral wall 411 of the second valve rod body 41 in contact with the upper surface of the peripheral wall 211 of the first valve rod body 21. When the connecting bolt 50 is screwed in, the second valve casing 41 is fastened to the first valve casing 21. In this fastened state, the discharge chamber 70 is formed on the bottom surface side of the stepped recess 21 a and the back pressure chamber 71 is formed on the end surface side of the fitting convex portion 42. Further, an annular groove 43 is formed on the outer periphery of the central portion in the protruding direction of the fitting convex portion 42, and an O-ring 45 that is in close contact with the inner peripheral wall surface of the fitting concave portion 22 is disposed in the annular groove 43 to provide a sealing property. Is secured.

  As shown in FIGS. 2 and 3, a stepped recess 49 having a small-diameter deep bottom surface 47 and a large-diameter shallow bottom surface 48 is formed on the upper surface of the second valve rod body 41. Furthermore, a guide hole 49 a for moving and guiding a stretching member 80 described later is formed from the center of the small-diameter deep bottom surface 47 to the lower end surface of the fitting convex portion 42. An annular groove 49b is formed on the inner peripheral surface of the guide hole 49a, and an O-ring 49c is disposed in the annular groove 49b, so that a main body shaft portion 81 of the extending member 80 and a guide hole 49a, which will be described later, are formed. Sealability is ensured.

  In the first embodiment, the fitting concave portion 22 of the first valve rod body 21 and the fitting convex portion 42 of the second valve rod body 41 are fitted in a circular cross section. That is, the fitting concave portion 22 is formed in a cylindrical hole, and the fitting convex portion 42 is formed in a column shape. Moreover, the diaphragm 60 installed on the installation surface 24 is formed in a disk shape.

  As shown in FIG. 3, an extending member 80 extending upward is disposed on one side surface (upper side surface in FIG. 3) of the diaphragm 60. In the first embodiment, the extending member 80 includes a main body shaft portion 81 having an axial shape, a joint shaft portion 82 extending downward from the lower end of the main body shaft portion 81 and having a smaller diameter than the main body shaft portion 81, A caulking shaft portion 83 extending downward from the lower end of the joining shaft portion 82 is provided on the same center line. Further, a first flange portion 85 and a second flange portion 86 are formed on the outer peripheral surface of the upper half portion of the main body shaft portion 81 of the extending member 80 at a predetermined interval in the axial direction (vertical direction). . The lower half of the main body shaft portion 81 of the extending member 80 is inserted so as to be movable in the vertical direction from above the guide hole 49a of the second valve rod 41 with the caulking shaft portion 83 facing downward. The caulking shaft portion 83 is inserted into a through hole formed in the center portion of the diaphragm 60. Thereafter, the end portion of the caulking shaft portion 83 protruding from the lower surface of the diaphragm 60 is caulked to form the caulking portion 84, whereby the extending member 80 is connected integrally with the diaphragm 60, and follows the deformation of the diaphragm 60. And moved up and down. In this state, the upper half portion of the main body shaft portion 81 projects upward from the guide hole 49 a, and the first flange portion 85 and the second flange portion 86 are disposed in the stepped recess 49 of the second valve rod body 41. Is done.

  As shown in FIG. 3, a damping member 95 that suppresses vibration of the diaphragm 60 is disposed between the valve rod 20 and the extending member 80. In the first embodiment, on the shallow bottom surface 48 of the stepped recess 49 of the second valve housing 41, a cylindrical fixed tube member 90 with the shallow bottom surface 48 as an attachment surface can be height-adjusted by a height adjusting mechanism 92. It is attached.

  The fixed cylinder member 90 is formed in a cylindrical shape having an inner diameter larger than the outer diameter of the first flange 85 and the second flange 86, and the first flange 85 and the inner peripheral surface thereof are formed on the inner peripheral surface thereof. An inner peripheral flange 91 disposed at an intermediate portion with the second flange portion 86 is formed. And the damping member 95 is arrange | positioned in the state clamped between the 1st collar part 85 and the inner peripheral flange 91, and between the inner peripheral flange 91 and the 2nd collar part 86, respectively.

  The damping member 95 is configured by a member having a characteristic that the rigidity is lower than that of the stretching member 80 and the damping property is high, for example, a member having a high damping property such as a vibration-proof rubber or a vibration-proof gel. In addition, in order to arrange the inner peripheral flange 91 of the fixed cylinder member 90 in the intermediate portion between the first flange portion 85 and the second flange portion 86 of the extending member 80, for example, the first flange portion 85 and the second flange portion 86 are disposed. At least one of the flange portions 86 is formed separately from the main body shaft portion 81 of the extending member 80, and then the separate flange portion is connected to the main body shaft by a coupling means such as a screw, clip, or caulking. It is also possible to fix to a predetermined position on the outer peripheral surface of the portion 81.

  In the first embodiment, the height adjustment mechanism 92 includes a plurality of fastening bolts 93 and a plurality of adjustment screws 94. That is, as shown in FIGS. 3 and 4, a plurality of bolt holes are provided in the fixed cylinder member 90 at a predetermined angle in the circumferential direction, and a plurality of female screws are provided at intermediate positions of the plurality of bolt holes. It is formed at a predetermined angle in the circumferential direction. Then, the adjustment screw 94 is screwed into the plurality of female screws, and the height of the fixed cylinder member 90 is adjusted with respect to the shallow bottom surface 48 in a state where the lower ends of the adjustment screws 94 are in contact with the shallow bottom surface 48 as attachment surfaces. When the fastening bolt 93 is screwed into the shallow bottom surface 48 as a mounting surface through a plurality of bolt holes of the fixed cylindrical member 90, the fixed cylindrical member 90 is higher than the shallow bottom surface 48 as the mounting surface of the second valve housing 41. It is adjusted and fastened.

  The hydrostatic bearing device according to the first embodiment is configured as described above. Therefore, the fluid pressurized by the pump P branches and flows into the discharge side inflow hole 32 and the back pressure side inflow hole 33 through the inlet 31 of the flow rate control mechanism 10. The fluid that has flowed into the discharge-side inflow hole 32 passes through the variable throttle channel between the diaphragm 60 and the valve seat surface 27, flows to the outlet 30, and is then supplied to the static pressure pocket 4 of the bearing body 2. A fluid film having a predetermined thickness is formed between the bearing surface of the bearing body 2 and the guide surface 7 of the movable body 6 by the fluid supplied to the static pressure pocket 4 to support the guide surface 7. After the fluid film is dynamically formed, it is maintained by repeatedly discharging to a drain and a discharge channel (not shown).

  Further, when a pressure difference is generated between the discharge chamber 70 and the back pressure chamber 71, the diaphragm 60 is deformed relatively gently (bending deformation) in accordance with the pressure difference, so that the diaphragm 60 and the valve seat surface 27 are deformed. The opening of the variable throttle channel is adjusted. When the diaphragm 60 is deformed, the extending member 80 moves up and down following the deformation. In the extending member 80, since the joining shaft portion 82 joined to the diaphragm 60 is formed with a smaller diameter than the main body shaft portion 81, the deformation of the diaphragm 60 can be reduced.

  When a disturbance force acts on the fluid film due to a disturbance load applied to the hydrostatic bearing 1, the pressure in the hydrostatic pocket 4 varies. For example, when the pressure in the static pressure pocket 4 is suddenly reduced, the pressure on the discharge chamber 70 side is suddenly reduced accordingly. Then, due to the pressure difference between the discharge chamber 70 and the back pressure chamber 71, the diaphragm 60 tends to be deformed (flexed deformation) rapidly downward. Then, the movement of the extending member 80 that follows the deformation of the diaphragm 60 is attenuated by the attenuation member 95. For this reason, rapid deformation of the diaphragm 60 can be suppressed (see FIG. 5). As a result, unexpected vibration of the diaphragm 60 can be suppressed, and a stable fluid bearing function can be obtained. That is, the rigidity of the fluid bearing can be increased.

  In the first embodiment, the first flange portion 85 of the extending member 80 and the inner peripheral flange 91 of the fixed cylindrical member 90 and the inner peripheral flange 91 of the fixed cylindrical member 90 and the second of the extending member 80 are used. It is possible to easily dispose the damping member 95 in a state of being sandwiched between each of the flange portions 86.

  In the first embodiment, the inner peripheral flange 91 is formed on the inner peripheral surface of the fixed cylinder member 90 fixed to the second valve rod body 41. For this reason, the inner peripheral flange 91 can be easily formed on the inner peripheral surface of the fixed cylinder member 90 as compared with the case where the inner peripheral flange is formed on the second valve housing 41.

  In the first embodiment, the inner peripheral flange of the fixed cylinder member 90 is adjusted by adjusting the height of the fixed cylinder member 90 in the moving direction of the extending member 80 with respect to the second valve housing 41 by the height adjusting mechanism 92. The damping member 95 can be disposed in an appropriate state between the first flange 85 and the second flange 86 of the extending member 80. For example, the deformation of the diaphragm 60 can be inhibited by the attenuation member 95, or the attenuation function of the attenuation member 95 can be suppressed from decreasing.

  In the first embodiment, the height adjusting mechanism 92 includes a plurality of fastening bolts 93 that fasten and fix the fixed cylinder member 90 to the shallow bottom surface 48 as the mounting surface of the second valve housing 41, A plurality of adjustment screws 94 for adjusting the height position of the fixed cylinder member 90 with respect to the shallow bottom surface 48 of the valve housing 41 are provided. First, the height position of the fixed cylinder member 90 is adjusted with a plurality of adjusting screws 94 with respect to the shallow bottom surface 48 of the second valve housing 41, and then a plurality of the shallow bottom surfaces 48 of the second valve housing 41 are arranged. By fastening and fixing the fixed cylinder member 90 with the fastening bolts 93, the fixed cylinder member 90 can be easily adjusted to a desired height position.

  Further, in the first embodiment, the damping member 95 is configured by a member having a characteristic that the rigidity is lower than that of the extending member 80 and the damping property is high, for example, a member having a high damping property such as a vibration proof rubber or a vibration proof gel. Therefore, rapid deformation of the diaphragm 60 can be satisfactorily suppressed.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, as shown in FIG. 6, the shape of the stretching member 180 and the configuration of the damping member are changed. The stretching member 180 includes a main body shaft portion 181 having a shaft shape, and a main body shaft portion. A joint shaft 182 extending downward from the lower end of the main shaft 181 and having a smaller diameter than the main body shaft portion 181 and a caulking shaft portion 183 extending downward from the lower end of the joint shaft portion 182 are provided on the same center line. doing. A small-diameter shaft portion 185 is formed on the same center at the upper end of the body shaft portion 181 so as to extend vertically upward to form a recess. Further, a bolt 196 is fastened to the distal end surface of the small diameter shaft portion 185 via a washer 197 in order to hold later-described damping members 195 a and 195 b around the small diameter shaft portion 185.

  On the other hand, with the shallow bottom surface 48 of the second valve housing 41 as an attachment surface, a cylindrical fixed cylinder member 190 is attached by the height adjustment mechanism 92 described in the first embodiment so that the height can be adjusted. An inner peripheral flange 191 having a central hole that is fitted and arranged at an intermediate portion in the axial direction of the small-diameter shaft portion 185 of the extending member 180 is formed on the lower inner peripheral surface of the fixed cylinder member 190. And in the recessed part 198 enclosed by the upper end surface of the main body shaft part 181 of the extending | stretching member 180, the outer peripheral surface of the small diameter shaft part 185, and the lower surface of the inner peripheral flange 191, the attenuation | damping which consists of rubber O-rings, for example The member 195a is disposed in a sandwiched state. Further, in a recess 199 surrounded by the upper surface of the inner peripheral flange 191, the outer peripheral surface of the small-diameter shaft portion 185, and the lower surface of the washer 197, a damping member 195 b made of, for example, a rubber O-ring is sandwiched. It is arranged in a state. Since the other structure of this Example 2 is comprised similarly to Example 1, the same code | symbol is attached | subjected with respect to the same component, and the description is abbreviate | omitted. Therefore, this second embodiment also has the same operational effects as the first embodiment.

  In addition, this invention is not limited to the said Example 1 and 2, In the range which does not deviate from the summary of this invention, it can implement with a various form. For example, in the first embodiment, the fixed cylinder member 90 is mounted on the shallow bottom surface 48 as the mounting surface of the second valve rod body 41 so that the height can be adjusted by the height adjusting mechanism 92. 92 is not necessarily provided. In the first embodiment, a plurality of flanges including the first flange 85 and the second flange 86 are formed on the outer peripheral surface of the main body shaft portion 81 of the extending member 80. However, there is only one flange. It may be. Moreover, in the said Example 1, although the case where the inner peripheral flange 91 with respect to the 1st collar part 85 of the extending | stretching member 80 and the 2nd collar part 86 was formed in the fixed cylinder member 90 was illustrated, the 2nd valve It is also possible to form the housing 41.

DESCRIPTION OF SYMBOLS 1 Hydrostatic fluid bearing 10 Flow control mechanism 20 Valve 21 21 1st valve housing 22 Fitting recessed part 41 2nd valve housing 42 Fitting convex part 48 Shallow bottom face (mounting surface)
60 Diaphragm 70 Discharge chamber 71 Back pressure chamber 80 Stretch member 85 First flange 86 Second flange 90 Fixed cylinder member 91 Inner flange 92 Height adjustment mechanism 93 Fastening bolt 94 Adjustment screw 95 Damping member

Claims (7)

A flow rate control mechanism for controlling the flow rate of fluid pumped from the pump,
The flow rate control mechanism includes a valve rod and a diaphragm that divides the inner chamber of the valve rod into a discharge chamber and a back pressure chamber,
In the diaphragm, an extending member that is connected to the diaphragm and moves relative to the valve rod following the deformation of the diaphragm extends in a direction perpendicular to the surface of the diaphragm,
A flow rate control mechanism, wherein a damping member that suppresses vibration of the diaphragm is disposed between the valve rod and the extending member. The flow rate control mechanism according to claim 1,
The extending member protrudes through the valve rod,
A flange or recess is formed on the protruding portion of the extending member, and an inner peripheral flange facing the flange or recess on the valve flange side with a predetermined distance in the moving direction of the extending member. Formed,
The flow rate control mechanism characterized in that the damping member is disposed in a state of being sandwiched between the flange portion or the concave portion and the inner peripheral flange. The flow rate control mechanism according to claim 2,
The flow rate control mechanism according to claim 1, wherein the inner peripheral flange is formed on an inner peripheral surface of a fixed cylinder member fixed to the valve rod. The flow rate control mechanism according to claim 3,
The flow rate control mechanism, wherein the fixed cylinder member is disposed so as to be height adjustable with respect to the valve rod by a height adjustment mechanism. A flow rate control mechanism according to claim 4,
The height adjusting mechanism includes a plurality of fastening bolts that fasten and fix the fixed cylinder member to the mounting surface of the valve rod, and an adjustment screw that adjusts the height position of the fixed cylinder member with respect to the mounting surface of the valve rod. And a flow rate control mechanism. The flow rate control mechanism according to any one of claims 1 to 5,
The flow rate control mechanism according to claim 1, wherein the damping member has characteristics of lower rigidity and higher damping property than the extending member.   A fluid bearing device, wherein a fluid whose flow rate is controlled by the flow rate control mechanism according to any one of claims 1 to 6 is supplied to a pocket of the fluid bearing.

Images