TWI615553B - Hydrostatic cylinder and method for establishing hydrostatic pressure - Google Patents

Description

Hydrostatic cylinder and method for establishing hydrostatic pressure

The invention relates to a counterweight for a machine tool, in particular to a hydrostatic cylinder and a method for establishing a hydrostatic pressure.

The vertical axis of the machine tool generally uses a weight mechanism to reduce the load on the motor. The simplest weight mechanism uses a weight. For example, the Republic of China Certificate No. M363350 patent is a linkage at the top of a machine head. The component is connected to a weight by bypassing the top of a column. This weight design is poor in dynamic characteristics due to the doubled head quality.

Another commonly used weighting mechanism is the use of a hydraulic cylinder, such as the Republic of China Certificate No. M317895, which is provided with a counterweight cylinder between the working head and the top of a column, the piston and piston of the counterweight cylinder. The rods need to be provided with sealing parts. Since the sealing parts must be closely matched with the cylinder block and the piston rod, the piston and the piston rod will generate considerable friction when moving. This frictional force will affect the micro-increment in addition to the dynamic characteristics. Therefore, the purpose of precision micro-feeding cannot be achieved.

Accordingly, it is an object of the present invention to provide a hydrostatic cylinder that reduces friction, has excellent dynamic characteristics, and can achieve precision micro-feeding.

Another object of the present invention is to provide a method for establishing hydrostatic pressure that can be used in a simple procedure and that can reduce friction, has good dynamic characteristics, and can achieve precision micro-feeding.

Thus, the hydrostatic cylinder of the present invention comprises a cylinder, a piston unit and a piston rod. The cylinder extends along an axis and includes a cylinder wall surrounding the axis and forming a piston chamber and at least one feed flow passage communicating with the piston chamber, the piston unit being slidably disposed on the piston along the axis a cavity, and the piston cavity is partitioned into a first region and a second region, the piston unit includes a first end surface adjacent to the first region, a first axis along the axis opposite to the first end surface and adjacent to a second end surface of the second region, an outer ring surface connected between the first end surface and the second end surface and opposite to the cylinder wall, and an oil guiding body extending from the first end surface toward the second end surface a plurality of holes, a plurality of flow passages communicating from the oil guiding holes toward the outer annular surface, and a plurality of pressure grooves recessed from the outer annular surface and respectively communicating with the divided flow passages, wherein the divided flow passages are in the shape of a class of holes, and respectively have a middle section communicating with the flow guiding hole, an outer side section disposed between the middle section and the outer annular surface, a closed section opposite to the outer side section and disposed between the middle section and the outer annular surface, and a setting a throttle portion between the middle portion and the outer side section, the piston rod along the axis Extension, corresponding to the inner end including a second end surface of the piston unit and connected to the one along the axis and opposite to the inner end and outer end of the extension provided on the outside of the cylinder.

A method for establishing a hydrostatic pressure, comprising the steps of: (A) preparing a hydrostatic cylinder comprising a cylinder, a piston unit and a piston rod, the cylinder extending along an axis and including a cylinder wall surrounding the axis and forming a piston chamber and at least one feed flow passage communicating with the piston chamber, the piston unit being slidably disposed along the axis of the piston chamber, and partitioning the piston chamber into a a first area and a second area, the piston unit includes a first end surface adjacent to the first area, a second end surface adjacent to the first end surface along the axis and adjacent to the second area, An outer annular surface connected between the first end surface and the second end surface and opposite to the cylinder wall, and a flow guiding hole extending from the first end surface toward the second end surface, and the plurality of guiding holes are opposite to the guiding hole a splitter passage communicating with the outer annular surface and a plurality of pressure grooves recessed from the outer annular surface and respectively communicating with the split runners, the split runners being in the shape of a class of holes, and each having a middle section communicating with the guide holes, An outer segment, a phase disposed between the middle segment and the outer annular surface a closed section disposed between the middle section and the outer annular surface and a throttle portion disposed between the middle section and the outer section, the piston rod extending along the axis, including a corresponding to the The two end faces are connected to the inner end of the piston unit and an outer end opposite to the inner end and extending outside the cylinder. (B) introducing a pressurized fluid from the feed passage to the piston chamber, and directing pressurized fluid from the flow guide to the split runners and the pressure tanks. (C) Using a pressurized fluid in the pressure tanks, a hydrostatic bearing can be formed between the piston unit and the cylinder.

The utility model has the advantages that the piston unit is provided with the flow guiding hole, the partial flow channels and the pressure grooves, and when the pressure fluid is introduced into the first region of the piston cavity, the piston unit corresponding to the pressure groove is corresponding to the piston unit A hydrostatic bearing is formed between the cylinders, and the piston unit is free from friction when moving relative to the cylinder, and the dynamic characteristics are good and the ultra-precision micro-feeding can be achieved.

10‧‧‧Cylinder

L‧‧‧ axis

11‧‧‧ piston cavity

111‧‧‧First area

112‧‧‧Second area

12‧‧‧Cylinder wall

13‧‧‧Under the cover

14‧‧‧Upper cover

15‧‧‧feed runner

16‧‧‧Extracting the runner

20‧‧‧piston unit

21‧‧‧Piston

211‧‧‧ first end face

34‧‧‧Locks

341‧‧‧shims

342‧‧‧Locking screws

40‧‧‧ bearing housing

41‧‧‧ spherical room

42‧‧‧ concave spherical surface

50‧‧‧Spherical bearings

51‧‧‧ convex spherical surface

52‧‧‧ center hole

60‧‧‧ piston rod

61‧‧‧Inside

62‧‧‧Outside

20’‧‧‧piston unit

212‧‧‧second end face

213‧‧‧ outer annulus

214‧‧ ‧ oil groove

215‧‧‧Inlet

216‧‧ ‧ runner

201‧‧‧ middle section

202‧‧‧Outer section

203‧‧‧Expanded section

205‧‧ Thread Department

217‧‧‧pressure tank

218‧‧ ‧ Confluence channel

219‧‧‧Connecting column

22‧‧‧ Throttling Department

30‧‧‧Support unit

31‧‧‧ lower support ring

311‧‧‧Lower hole

32‧‧‧Upper support ring

321‧‧‧Set of holes

33‧‧‧ balls

21’‧‧‧Piston

212'‧‧‧ second end

216’‧‧ ‧ runner

219’‧‧‧ Connection column

23’‧‧‧pressure tank

24’‧‧‧drain

30’‧‧‧Support unit

31'‧‧‧ bottom end

32’‧‧‧ top surface

33’‧‧‧ hole

21"‧‧‧Piston

216" ‧ ‧ split runner

30”‧‧‧Support unit

40"‧‧‧ bearing housing

42"‧‧‧ concave spherical surface

43”‧‧‧pressure tank

44”‧‧‧Drainage channel

50"‧‧"spherical bearings

51"‧‧‧ convex spherical surface

Other features and advantages of the present invention will be apparent from the embodiments of the present invention, wherein: Figure 1 is a cross-sectional view of a first embodiment of a hydrostatic cylinder of the present invention; Figure 2 is a cross-sectional view of a first embodiment of the hydrostatic cylinder of the present invention; Figure 3 is a cross-sectional view taken along line III-III of Figure 1; Figure 4 is a partially enlarged schematic view of a second embodiment of the hydrostatic cylinder of the present invention; and Figure 5 is a fluid of the present invention A partially enlarged schematic view of a third embodiment of a hydrostatic cylinder.

Referring to FIG. 1 , FIG. 2 and FIG. 3 , a first embodiment of a hydrostatic cylinder of the present invention comprises a cylinder 10 , a piston unit 20 , a supporting unit 30 , a bearing seat 40 , a ball bearing 50 , and A piston rod 60.

The cylinder block 10 extends along an axis L and has a hollow cylindrical shape, and includes a cylinder wall 12 surrounding the axis L and forming a piston chamber 11, and a lower cover 13 disposed at one end of the cylinder wall 12, An upper cover 14 opposite to the lower cover 13 and sealed at the other end of the cylinder wall 12, a feed flow path 15 corresponding to the lower cover 13 and an extraction flow corresponding to the upper cover 14 Road 16. In addition, the upper cover 14 and the outlet flow path 16 may be omitted and the top of the second area 112 may be directly connected to a return groove (not shown).

The piston unit 20 is slidably disposed in the piston chamber 11 along the axis L, and the piston chamber 11 is partitioned into a first region 111 communicating with the feed channel 15 and communicating with the outlet channel a second region 112 of the piston unit 20, the piston unit 20 includes a piston 21 and a plurality of throttle portions 22, the piston 21 having a first end surface 211 adjacent to the first region 111, and a direction L along the axis L opposite to the first portion An end surface 211 and a second end surface 212 adjacent to the second region 112, and an outer annular surface 213 connected between the first end surface 211 and the second end surface 212 and opposite to the cylinder wall 12 An oil collecting groove 214 recessed in the outer ring surface 213, a flow guiding hole 215 disposed along the axis L and extending from the first end surface 211 toward the second end surface 212, and most of the guiding hole 215 facing the outer annular surface a branching passage 216 communicating with and extending in a radial direction perpendicular to the axis L, a plurality of pressure grooves 217 recessed from the outer annular surface 213 and respectively communicating with the divided passages 216, and a plurality of recesses 217 recessed from the outer annular surface 213 And extending parallel to the axis L and communicating with the bus passages 218 of the oil collecting grooves 214, one end of each of the collecting channels 218 is connected to the first Two end faces 212 and connectable To the second region 112. The piston 21 also has a connecting post 219 projecting from the second end face 212 and extending along the axis L.

The sub-flow passages 216 are in the shape of a class of holes, and have a middle portion 201 connected to the flow guiding hole 215, an outer side portion 202 disposed between the middle portion 201 and the outer annular surface 213, and a side opposite to the outer side portion. And a closed portion 203 disposed between the middle portion 201 and the outer ring surface 213 and a threaded portion 205 disposed at the middle portion 201 and the outer portion 202. The pressure grooves 217 are respectively connected to the outer side portions. 202.

The throttling portions 22 of the present embodiment are formed as separate parts and are respectively mounted to the sub-flow passages 216 and are screw-locked to the threaded portions 205, respectively. In addition, the throttling portions may be directly formed into a reduced diameter hole shape and disposed between the divided flow passages and the pressure grooves (not shown), and may also achieve the purpose of throttling.

The support unit 30 is coupled between the piston unit 20 and the piston rod 60, and includes a lower support ring 31 radially disposed on the second end surface 212, and a lower support ring 31 disposed along the axis L. a side upper support ring 32, a plurality of balls 33 disposed between the lower support ring 31 and the upper support ring 32, and a lock member 34 for locking the upper support ring 32 to the piston 21, the upper support The ring 32 has the ability to be radially offset relative to the lower support ring 31. The lower support ring 31 has a sleeve hole 311 disposed in the connecting post 219, and there is no clearance between the lower sleeve hole 311 and the connecting post 219, and the lower support ring 31 is radially opposite to the piston 21 Positioning, the upper support ring 32 has a set of upper sleeve holes 321 disposed on the connecting post 219, the upper sleeve hole 321 and the connecting post A clearance is created between 219, with which the upper support ring 32 is radially displaceable relative to the connecting post 219. The locking member 34 has a spacer 341 disposed on the large diameter section of the upper sleeve hole 321 and a locking screw 342 disposed on the spacer 341 and locked to the connecting post 219.

The bearing block 40 is coupled to the piston 21 through the support unit 30. The bearing block 40 of the embodiment is fixed on the top of the upper support ring 32 and has a concave spherical surface 42 defining a spherical cavity 41. The spherical chamber 41 is disposed along the axis L.

The spherical bearing 50 is mounted in the spherical chamber 41 and is rotatable relative to the bearing housing 40, and has a convex spherical surface 51 attached to the concave spherical surface 42 and a pair of central holes 52 disposed on the axis L.

The piston rod 60 extends along the axis L, and includes an inner end 61 corresponding to the second end surface 212 and connected to the central hole 52 of the spherical bearing 50, and a side opposite to the inner end 61 along the axis L. An outer end 62 is provided outside the cylinder 10.

As shown in FIG. 1 to FIG. 3, when the piston unit 20 is raised, pressure fluid is introduced into the first region 111 of the piston chamber 11 by the feed flow passage 15, and the piston unit 20 can be pushed toward the piston unit 20. The direction of the flow path 16 is taken out, and at the same time, the pressure fluid (which may be pressurized oil in the embodiment) flows through the flow guiding hole 215, and the pressure fluid passes through the throttling portions 22 by the arrangement of the equal dividing passages 216. The outer section 202 flows to the pressure grooves 217, and a hydrostatic bearing is formed between the piston unit 20 corresponding to the pressure groove 217 and the cylinder 10. At the same time, the outer annular surface 213 of the piston 21 and the cylinder wall 12 are still There is a gap which can slide relative to each other, and a pressure fluid in the gap between the outer ring surface 213 and the cylinder wall 12 penetrates and forms an oil film, and the hydrostatic bearing and the oil film can make the oil film When the piston 21 moves relative to the cylinder 10, no friction is generated, and the dynamic characteristics are better. The arrangement of the hydrostatic cylinder can achieve the purpose of balancing the weight, and the utility machine can be used to drive a ball screw (not shown). The load of a drive motor. The pressure fluids of the pressure tanks 217 are collected again into the oil collection grooves 214, and finally the second flow paths 218 are drained to the second region 112 (the fluid in the second region 112 is at normal pressure), and finally It is discharged from the take-out flow path 16 to facilitate recycling.

When the piston unit 20 is lowered and moved toward the direction in which the feed flow path 15 is provided, and the pressure fluid in the first region 111 is pressed by the piston 21, the pressure fluid is again introduced by the flow guiding hole 215. Also, a hydrostatic bearing is formed between the piston unit 20 corresponding to the pressure groove 217 and the cylinder block 10. Therefore, when the piston unit 20 is moved bidirectionally with respect to the cylinder block 10, it is preferable to produce a hydrostatic bearing. Dynamic characteristics.

The outer end 62 of the piston rod 60 of the hydrostatic cylinder of the present invention can be coupled to a machine tooling head (not shown) and connected to the spherical bearing 50 by the inner end 61 of the piston rod 60. The bearing 50 is nested with the bearing housing 40. The bearing housing 40 is fixed to the upper support ring 32. The upper support ring 32 is locked to the connecting post 219 of the piston 21 through the locking member 34. The movable rod 60 can be The weight of the machine tool head is supported by the piston unit 20.

The steel ball 33 between the upper support ring 32 and the lower support ring 31 can absorb the radial deviation of the axial direction of the piston rod 60 with respect to the axis L. By the cooperation of the concave spherical surface 42 of the bearing housing 40 and the convex spherical surface 51 of the spherical bearing 50, the axial deviation of the axis L of the hydrostatic cylinder from the axial direction of the piston rod 60 can be absorbed, so that the hydrostatic cylinder can be improved. The assembly is improved and the smoothness of the movement of the piston 21 is improved.

As further shown in Figures 1 to 3, the method of the present invention for establishing hydrostatic pressure comprises the following steps:

Step 1: Preparing a hydrostatic cylinder comprising a cylinder 10, a piston unit 20, a support unit 30, a bearing housing 40, a ball bearing 50 and a piston rod 60. 10. The detailed structure of the piston unit 20, the support unit 30, the bearing housing 40, the spherical bearing 50, and the piston rod 60 is as described above.

Step 2: Introducing pressurized fluid from the feed flow passage 15 to the piston chamber 11 and directing pressurized fluid from the flow guide hole 215 to the split runners 216 and the pressure tanks 217.

Step 3: Using the pressure fluid in the pressure grooves 217, a hydrostatic bearing can be formed between the piston unit 20 and the cylinder 10.

As shown in FIG. 4, the second embodiment of the hydrostatic cylinder of the present invention differs from the first embodiment in that the second end surface 212' of the piston unit 20' has a plurality of pressure grooves 23' and most of them are respectively connected to a guide channel 24' between the pressure groove 23' and the branching passage 216'. The supporting unit 30' is made in one piece and has a second end surface 212' An opposite bottom end surface 31', a top end surface 32' opposite the bottom end surface 31' along the axis L, and a sleeve hole 33' extending from the bottom end surface 31' toward the top end surface 32' and disposed along the axis L . The inner diameter of the sleeve hole 33' is larger than the outer diameter of the connecting post 219', and the supporting unit 30' has a radial displacement capability relative to the piston unit 20', so that the supporting unit 30' can absorb the The radial deviation of the axial direction of the piston rod 60 relative to the axis L. The pressure fluid can be drained to the pressure groove 23' to create a hydrostatic bearing between the bottom end surface 31' and the second end surface 212', and the support unit 30' and the piston unit 20' can be The function of the hydrostatic bearing is formed and the smoothness of the movement of the piston 21' is improved.

As shown in FIG. 5, the third embodiment of the hydrostatic cylinder of the present invention differs from the second embodiment in that the bearing housing 40" further has a pressure groove 43 that can be recessed from the concave spherical surface 42". And a drain passage 44" that is connectable to the pressure groove 43' and the branch passage 216" through the support unit 30", and functions to generate a hydrostatic bearing between the concave spherical surface 42" and the convex spherical surface 51" The hydrostatic bearing is formed between the bearing housing 40" and the spherical bearing 50", and the smoothness of the movement of the piston 21" is improved.

It should be noted that the above embodiment of the present invention is described by a counterweight cylinder of a machine tool. In fact, the technical features of the present invention can also be applied to a piston and a cylinder (not shown) of a compressor or an engine, and Keep the compressor or engine running smoothly.

In summary, the hydrostatic cylinder of the present invention has a simple overall structure and is easy to manufacture, and a hydrostatic bearing can be formed between the cylinder and the outer annular surface, so that the piston unit can be opposite to the cylinder. No friction is generated during exercise, the dynamic characteristics are good, and the ultra-precision micro-feeding can be achieved, and the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still The scope of the invention is covered.

10‧‧‧Cylinder

22‧‧‧ Throttling Department

L‧‧‧ axis

30‧‧‧Support unit

11‧‧‧ piston cavity

31‧‧‧ lower support ring

111‧‧‧First area

32‧‧‧Upper support ring

112‧‧‧Second area

33‧‧‧ balls

12‧‧‧Cylinder wall

40‧‧‧ bearing housing

13‧‧‧Under the cover

50‧‧‧Spherical bearings

14‧‧‧Upper cover

60‧‧‧ piston rod

15‧‧‧feed runner

61‧‧‧Inside

16‧‧‧Extracting the runner

62‧‧‧Outside

20‧‧‧piston unit

216‧‧ ‧ runner

21‧‧‧Piston

215‧‧‧Inlet

Claims (8)

A hydrostatic cylinder comprising: a cylinder extending along an axis and including a cylinder wall surrounding the axis and forming a piston chamber and at least one feed flow passage communicating with the piston chamber; a piston unit, The piston chamber is slidably disposed along the axis, and the piston chamber is partitioned into a first region and a second region, the piston unit includes a first end surface adjacent to the first region, and an axis along the axis a second end surface opposite to the first end surface and adjacent to the second area, an outer annular surface connected between the first end surface and the second end surface and opposite to the cylinder wall, and the first end a flow guiding hole extending toward the second end surface, a plurality of flow dividing passages communicating from the flow guiding hole toward the outer annular surface, and a plurality of pressure grooves recessed by the outer annular surface and respectively communicating with the divided flow passages, and the like The runners are in the shape of a class of holes, and each has a middle section communicating with the flow guiding hole, an outer section disposed between the middle section and the outer annular surface, a side opposite to the outer section, and disposed at the middle section and the outer section a closed section between the torus and a portion disposed between the middle section and the outer section a throttle portion; and a piston rod extending along the axis, including an inner end corresponding to the second end surface and connected to the piston unit and a side opposite to the inner end and extending outside the cylinder Outer end. The hydrostatic cylinder according to claim 1, further comprising a supporting unit coupled between the piston unit and the piston rod, the supporting unit comprising a lower supporting ring radially positioned on the second end surface, An upper support ring disposed on one side of the lower support ring along the axis and a plurality of upper support rings and the upper support A ball between the brace rings, the upper support ring having the ability to be radially offset relative to the lower support ring. The hydrostatic cylinder of claim 2, further comprising a bearing housing that is positionable relative to the upper support ring and a ball bearing coupled to the piston rod and rotatable relative to the bearing housing, the bearing The seat has a concave spherical surface defining a spherical cavity, the spherical bearing being mounted in the spherical cavity and having a convex spherical surface attached to the concave spherical surface. The hydrostatic cylinder according to claim 3, wherein the piston unit further has a connecting post protruding from the second end surface and extending along the axis, the lower supporting ring is sleeved on the connecting post and along the diameter Positioning is created relative to the piston unit, the upper support ring being radially displaceable relative to the connecting post. The hydrostatic cylinder according to claim 3, wherein the bearing housing further has at least one pressure groove recessed from the concave spherical surface and at least one drainage passage through the support unit to communicate with the pressure groove and the flow dividing channel A hydrostatic bearing can be produced between the concave spherical surface corresponding to the pressure groove and the convex spherical surface. The hydrostatic cylinder of claim 1, further comprising a support unit coupled between the piston unit and the piston rod, the support unit being unitary and having a bottom end surface opposite to the second end surface, a top end surface opposite the bottom end surface along the axis and a sleeve hole extending from the bottom end surface toward the top end surface and disposed along the axis L, the piston unit further having a protrusion from the second end surface and along the An axially extending connecting post having an inner diameter greater than an outer diameter of the connecting post and having the support unit radially offset relative to the piston unit. The hydrostatic cylinder according to claim 2 or claim 6, wherein the second end surface of the piston unit has at least one pressure groove and at least one drainage channel respectively communicating between the pressure groove and the branch flow path. A method for establishing a hydrostatic pressure, comprising the steps of: (A) preparing a hydrostatic cylinder comprising a cylinder, a piston unit and a piston rod, the cylinder extending along an axis and including a cylinder wall surrounding the axis and forming a piston chamber and at least one feed flow passage communicating with the piston chamber, the piston unit being slidably disposed along the axis of the piston chamber, and partitioning the piston chamber into a a first area and a second area, the piston unit includes a first end surface adjacent to the first area, a second end surface adjacent to the first end surface along the axis and adjacent to the second area, An outer annular surface connected between the first end surface and the second end surface and opposite to the cylinder wall, and a flow guiding hole extending from the first end surface toward the second end surface, and the plurality of guiding holes are opposite to the guiding hole a splitter passage communicating with the outer annular surface and a plurality of pressure grooves recessed from the outer annular surface and respectively communicating with the split runners, the split runners being in the shape of a class of holes, and each having a middle section communicating with the guide holes, An outer segment, a phase disposed between the middle segment and the outer annular surface a closed section disposed between the middle section and the outer annular surface and a throttle portion disposed between the middle section and the outer section, the piston rod extending along the axis, including a corresponding to the a second end surface connected to the inner end of the piston unit and an outer end opposite to the inner end and extending outside the cylinder; (B) introducing a pressure fluid from the feed passage into the piston chamber And directing pressurized fluid from the flow guiding orifice to the split runners and the pressure tanks; and (C) Using a pressurized fluid in the pressure tanks, a hydrostatic bearing can be formed between the piston unit and the cylinder.