CN115789011A - Four-rod piston oil cylinder, four-jaw floating chuck and numerical control double-drive cylindrical grinding machine - Google Patents

Abstract

The invention relates to a four-rod piston oil cylinder, a four-jaw floating chuck and a numerical control double-drive cylindrical grinding machine. The four-rod piston oil cylinder is provided with an annular cylindrical cylinder body, an annular piston is arranged in the cylinder body, and a plurality of piston rods are arranged on one side or two sides of the annular piston. The four-jaw floating chuck is provided with an oil cylinder and jaws, the oil cylinder adopts a four-rod piston oil cylinder, the jaws are fixedly arranged at the outer ends of respective swing arms, swing arm shafts are arranged at the inner ends of the swing arms, the swing arm shafts are arranged on a floating connecting frame, the swing arms are also provided with long grooves, pin columns are arranged at the outer ends of the piston rods, the pin columns are inserted into the long grooves of the corresponding swing arms and are in sliding fit with the corresponding long grooves, and the floating connecting frame is annular and is connected to the front side of the cylinder body in a floating mode. The headstock and the tailstock of the numerical control double-drive cylindrical grinding machine are provided with corresponding centers for centering a workpiece, and the spindles of the headstock and the tailstock are provided with four-jaw floating chucks. The chuck can be used together with the tip, and does not interfere with feeding and discharging of a workpiece.

Description

Four-rod piston oil cylinder, four-jaw floating chuck and numerical control double-drive cylindrical grinding machine

Technical Field

The invention relates to a four-rod piston oil cylinder, a four-jaw floating chuck adopting the oil cylinder and a numerical control double-drive cylindrical grinding machine adopting the floating chuck.

Background

The piston type oil cylinder (or called hydraulic cylinder) is a common oil cylinder form and is provided with a cylindrical cylinder body, a movable piston is arranged in the cylinder body, a piston rod is coaxially arranged on the piston (the axes are the same or are positioned on the same straight line), the piston rod can be unidirectional, the corresponding oil cylinder is called a single-rod type oil cylinder, the piston rod can also be bidirectional (or both sides of the piston rod are provided with the piston rod), and the corresponding oil cylinder is called a double-rod type oil cylinder. The piston divides the space in the cylinder body into two cavities (or called oil cavities), and the piston moves under the action of pressure difference at two sides, so that the piston rod is driven to move. The oil cylinder has at most one piston rod at any side for outputting, when a plurality of pieces are required to be driven to synchronously move simultaneously, a plurality of synchronous oil cylinders are required to be arranged for respectively driving the pieces to be driven, or a complex transmission mechanism is arranged for realizing conversion from one-way output to multi-way output.

The processing machinery such as grinding machine to the centre gripping of work piece adopts three-jaw chuck more, is equipped with three jack catch on the chuck, jack catch and chuck swing joint for each jack catch can be along the radial rectilinear movement of chuck, when needs clamping work piece, arranges the corresponding end of work piece in between each jack catch, and the inside removal of each jack catch of drive is pressed from both sides the corresponding end of work piece tightly, when the chuck is rotatory, drives the synchronous rotation of work piece.

For example, chinese patent document CN207431306U discloses a lathe fixture, which comprises a base, a linkage rotating shaft is installed on the positive lower surface of the base, the linkage rotating shaft and the base are integrally formed, the linkage rotating shaft is forged by No. 45 steel, a three-jaw chuck is installed on the upper surface of the base, a clamping device is installed at the gap of the three-jaw chuck, the clamping device is movably connected with the three-jaw chuck through a sliding groove, the surface of the clamping device is provided with an outside of a cylinder, a cylinder shell is forged by impact-resistant steel titanium alloy, a cylinder piston is installed in the middle of the cylinder shell, the cylinder piston is in sleeve fit with the cylinder shell, a piston rod is arranged in the middle of the cylinder piston, the piston rod is in transmission connection with the cylinder piston, a positioning groove is installed at the bottom of the piston rod, the positioning groove is made of aluminum alloy with extremely high hardness, two valves are installed at the bottom of the cylinder shell, the valves are fixedly connected with the cylinder shell through a buckle, a workpiece is installed in the middle of the three-jaw chuck, calipers are installed at the top of the cylinder piston, the calipers are fastened and connected with the cylinder piston through threads, the cylinder shell is made of wear-resistant nickel alloy, and the cylinder is provided with the cylinder shell, and the cylinder is connected with the glue.

These prior arts have features and are respectively suitable for the respective occasions, but have limitations at the same time. For example, when a plurality of pieces of the oil cylinder are required to be driven synchronously, the oil cylinder is required to be driven separately, which not only complicates the whole device, but also makes it difficult to maintain the synchronization of the oil cylinders with high accuracy in cases where the requirement for synchronization is high, and in some cases, even makes it difficult to provide a space for installing a plurality of oil cylinders. For another example, for an existing chuck, the position of the chuck on a machine tool (a head or a tail) is not changed, and the chuck is often blocked in a feeding and discharging area of a workpiece, and when the workpiece is mechanically fed and discharged (for example, by a manipulator), a complex movement mode of the workpiece is required to be implemented to avoid blocking of the chuck, and otherwise, the chuck is not suitable for being used at the same end of the workpiece together with a tip, or collision between the centering of the tip and the centering of the chuck occurs, so that the use range is limited, and the chuck cannot be used or cannot meet the precision requirement in some occasions.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a four-rod piston oil cylinder, a four-jaw floating chuck adopting the oil cylinder and a numerical control double-drive cylindrical grinding machine adopting the floating chuck.

The technical scheme of the invention is as follows: the four-rod piston oil cylinder is provided with an annular cylinder body (or called an oil cylinder body) with an annular cylinder shape (the cross section of the cylinder body is of an annular/circular ring-shaped cylindrical structure), an annular piston is arranged in the cylinder body, and a plurality of piston rods are arranged on one side or two sides of the annular piston.

Preferably, the piston rods located on the same side are equally spaced (equiangular) on the same circumference.

Further, a piston rod may be provided on only one side of the piston.

Further, the number of the piston rods provided on one side of the piston is four, and may be three, two, or another number.

Furthermore, a cylinder cover (or called an oil cylinder cover) is arranged on the cylinder body, and a plurality of piston rod holes for respectively penetrating through the corresponding piston rods are formed in the cylinder cover.

The four-jaw floating chuck is provided with an oil cylinder and jaws, the oil cylinder adopts any four-rod piston oil cylinder disclosed by the invention, the jaws are fixedly arranged at the outer ends (jaw connecting ends or called driving output ends) of respective swing arms, the inner ends (piston rod connecting ends or called driving input ends) of the swing arms are provided with swing arm shafts (for example, pin shafts), the swing arm shafts are arranged on a floating connecting frame so as to allow the swing arms to rotate/swing (or called overturn) relative to the floating connecting frame, the swing arms are also provided with elongated slots (elongated holes, the length direction of which is the swing arm extending direction of a corresponding area), the outer ends of the piston rods are provided with pin columns, the pin columns are inserted into the elongated slots of the corresponding swing arms and are in sliding fit with the corresponding elongated slots, the floating connecting frame is annular and is in floating connection with the front side of the cylinder body.

Furthermore, the number of the claws is four, or three, two or other numbers, the number of the piston rods on the oil cylinder is also 4, or three, two or other numbers, and each piston rod is respectively used for driving the corresponding claw.

Furthermore, the swing arm is bent, the long groove is formed in the inner section (the part from the bent part to the end part of the inner end) of the swing arm, the swing/turning range of the swing arm is 90 degrees in the stroke range of the piston rod, and the stroke range of the piston rod and the stroke range of the swing arm can be adapted to each other through the matching of the sizes and the shapes of all the parts.

Preferably, a plurality of through holes for passing through screws of the floating frame (screws for connection of the floating frame) are arranged on the radial outer side of the floating frame, screws of the floating frame (screws for short) pass through the corresponding through holes and are screwed at the front end (for example, a cylinder cover) of the cylinder body, a gasket (or a backing plate) is arranged between the screw head and the floating frame, first steel balls (including non-steel spherical parts) are arranged between the two gaskets and the front side surface of the floating frame, the two first steel balls (accordingly, the gasket provided with the first steel balls between the two first steel balls and the front side surface of the floating frame) are located in the same diameter direction, two second steel balls are arranged between the radial inner side (facing the side of the cylinder body) of the floating frame and the front end surface of the cylinder body and located in the same diameter direction, an elastic spacer sleeve (for example, a rubber spacer sleeve) is sleeved on the screws of the floating frame, and the elastic spacer sleeve is located between the through holes on the floating frame through which the screws of the floating frame pass through screws of the floating frame, so as to realize axial floating and radial floating.

Further, the jack catch includes the jack catch seat and installs (for example, inlay the dress) the jack catch main part (or for short the jack catch) on the jack catch seat, and adjusting screw's outer end (or called jack catch link) is connected in the outside of jack catch seat, and the inner end (or called swing arm link) is screwed in the outer end of corresponding swing arm and is exposed from the opposite side of the corresponding screw hole on the swing arm, and the part that exposes has screwed connection has set nut.

A headstock and a tailstock of the numerical control double-drive cylindrical grinding machine are provided with corresponding apexes for positioning (centering) two ends of a workpiece, chucks are respectively arranged on main shafts of the headstock and the tailstock, and the chucks adopt any four-jaw floating chuck disclosed by the invention.

The invention has the beneficial effects that: because the annular piston is provided with a plurality of identical piston rods, the piston drives the piston rods to move together, and compared with the method that a plurality of synchronous oil cylinders are adopted or a complex transmission mechanism is adopted to convert the single-path output of the existing oil cylinder into multi-path synchronous output, the synchronous multi-path output device has simple structure and can also keep the synchronism with higher precision. Because the four-rod piston oil cylinder with multi-path output is adopted, each piston rod which is synchronously output respectively drives each corresponding claw on the four-claw floating chuck, and the high-precision synchronism of each claw is realized; the cylinder body of the oil cylinder can rotate, so that hydraulic drive of the chuck is realized, and automatic control of the chuck can be realized by combining an automatic control technology; the claw is driven by the piston rod through the crank rocker mechanism, so that the claw, the swing arm and the like can be turned over, the workpiece is released and leaves a feeding and discharging area, and the interference on the feeding and discharging operation of a manipulator and the like is avoided; because the swing arm pin shaft is arranged on the floating connecting frame, axial and radial floating can be realized through the floating connecting plate, the conflict between tip positioning and clamp positioning is effectively solved, and a workpiece can be clamped by a clamp (a chuck) while tip positioning is adopted, so that the workpiece is driven to rotate at high precision by axes determined by tips at two sides.

Drawings

Fig. 1 is a front view schematically showing a chuck according to the present invention (a state of clamping a workpiece);

fig. 2 is a schematic front view of a chuck according to the present invention (a work released state);

FIG. 3 is a side (Z-direction) schematic view of a chuck in accordance with the present invention;

FIG. 4 is a schematic view of a chuck actuator/quick adjustment mechanism according to the present invention (for adjustment to accommodate different workpiece outer circle dimensions);

FIG. 5 is a diagrammatic view of chuck movement in accordance with the present invention;

FIG. 6 is a schematic diagram of a piston hydraulic system to which the present invention relates;

FIG. 7 is a schematic view of the working state of the charging and discharging of the grinding machine according to the present invention;

FIG. 8 is a side view of a cylinder according to the present invention;

FIG. 9 is a schematic view of the piston and rod combination of a cylinder according to the present invention;

fig. 10 is a schematic view of the construction of a floating link mechanism/floating link according to the present invention.

The labels in the figure are: a1: an oil cylinder end cover; a2: a seal ring; a3: a cylinder body; a4: a seal ring; a5: a swivel joint (or first swivel joint); a6: bearings (swivel joint bearings); a7: a bearing spacer bush; a8: a swivel joint (or a second swivel joint); a9: a seal ring; a10: a seal ring; a11: a screw; a12: a screw; b1: a piston; b2: piston rods (four); b3: a nut; b4: a seal ring; c1: screws (floating frame screws); c2: a first steel ball; c3: a second steel ball; c4: a floating connection frame; c5: a rubber spacer bush; d1: a flexible jaw; d2: a set screw; d3: swinging arms; d4: positioning a nut; d5: adjusting the screw rod; d6: a pin; d7: a pin shaft; e1: a workpiece (grinding workpiece); e2: a tip; e3: spindles (headstock spindles); f1: an oil pump; f2: a pressure reducing valve; f3: a pressure gauge; f4: an electromagnetic directional valve; f5: a hydraulic control check valve; f6: an oil cylinder; g1: a head frame; g2: a four-jaw float chuck; g3: a tailstock; g4: a robot arm.

Detailed Description

Compared with the prior art, the invention mainly meets the following functional requirements of the headstock and tailstock automatic chucks of the numerical control double-drive cylindrical grinding machine:

1) When the manipulator loads and unloads, the chuck is required to exit the loading and unloading area, so that interference is avoided;

2) Double-drive clamping;

3) The workpiece is ground and finished, and the claw cannot scratch the surface of the workpiece;

4) The chuck should be capable of floating without adversely affecting center runout of the workpiece as it is driven.

The invention relates to the following main technical concepts:

1) The rotary oil cylinder (the main body part of the cylinder body is in a rotary body shape) of the four-rod piston is provided with an axial central through hole to allow a tip to pass through and can be directly arranged on a headstock and a tailstock;

2) The clamping jaw is made of polyurethane material, and has the characteristics of flexible clamping and no scratch on a workpiece;

3) The self-locking function is realized by the wedge of the elastic clamping jaw and the hydraulic control one-way valve after the workpiece is clamped by adopting the transmission of a crank rocker mechanism.

Referring to fig. 1-10, the chuck of the present invention is primarily concerned with four parts, a hollow cylinder and swivel joint (primarily the parts beginning with a in the reference numerals), a four-piston rod hollow piston (primarily the parts beginning with B in the reference numerals), a floating link (primarily the parts beginning with C in the reference numerals), and a flexible clamping jaw (primarily the parts beginning with C in the reference numerals).

Example 1: four-jaw floating chuck

Referring to fig. 1-3, when the chuck is in a clamping state (as shown in fig. 1) to a loosening state (as shown in fig. 2), a polyurethane-made clamping jaw (or called flexible clamping jaw, or clamping jaw for short) D1 (an upper clamping jaw shown in fig. 2) swings clockwise by 90 °, or the clamping jaw D1 should turn 90 ° in a direction away from a workpiece, so as to leave away from a grinding workpiece (or workpiece for short) E1, and leave a moving space for feeding and discharging a manipulator (as shown in fig. 7) to avoid interference.

An oil cylinder end cover A1 is arranged on a cylinder body A3 of the four-rod piston oil cylinder, the oil cylinder end cover A1 and the main body (the rest part) of the cylinder body form a circular cylinder body together, the radial central part of the cylinder body is hollow and can be regarded as an axial central through hole which is used for penetrating through a centre or sleeved outside the centre, a piston B1 in the cylinder body A3 is also in an annular shape, an inner circle (inner peripheral surface) and an outer circle (outer peripheral surface) are respectively in sealing sliding fit with the circular cylinder wall at the inner side and the outer side of the circular cylinder wall, piston rods are distributed at equal intervals in the circumferential direction and extend out of the cylinder body from one end (which can be called as a front end) to drive a part/mechanism to be driven externally, when the four-rod piston oil cylinder is used for grinding a headstock (or tailstock), the cylinder body can be fixed on a headstock (or tailstock) main shaft E3 or a headstock (or tailstock) rotary drive plate by four screws A12, two rotary joints A5 are arranged on the outer side cylinder wall of the cylinder body and are used for connecting an oil pipeline of a hydraulic oil system, the two rotary joints A5 are respectively communicated with oil cavities on two sides of a piston through corresponding through holes on the outer side cylinder wall of the cylinder body, according to the required movement direction of the piston rod, pressure air or hydraulic oil is pumped in through the hydraulic oil system to push the piston B1 to move leftwards (according to the direction shown in figure 1) or rightwards (or backwards), four piston rods B2 fixed on the piston B1 do extension movement or retraction movement, two sides of the outer end of each piston rod are respectively provided with a pin D6, two pins are symmetrical to form a group and are used for driving/transmitting the same swing arm D3, and two symmetrical side plates are arranged on the driving input side (the connecting side of the piston rod) of the swing arm, the two side plates are provided with an elongated slot (elongated through hole) and a round hole which correspond to each other, the outer end of the piston rod is positioned between the two side plates of the swing arm, the pin columns D6 on the two sides are respectively inserted into the elongated slots on the corresponding side plates and are in sliding fit with the slot walls of the elongated slots so as to slide in the elongated slots on the swing arm D3, and further the swing arm D3 is driven to turn over in the direction of clamping a workpiece or in the reverse direction of keeping away from the workpiece (for example, the swing arm rotates anticlockwise in the upper direction shown in fig. 1), the turning range can be 90 degrees, the swing center is a pin shaft D7 fixed on a floating connecting frame C4, the pin shaft D7 is arranged on a pin shaft connecting part extending out of the floating connecting frame, the pin shaft connecting part is positioned between the two side plates of the swing arm, each side is provided with a pin shaft D7, the two pin shafts are respectively inserted into the round holes on the corresponding side plates, and are connected through corresponding bearings so as to realize the rotary fit with the round holes. By adopting the two-side transmission mode, the force balance is facilitated.

The number of swing arms D3 is typically 4, and correspondingly, the number of piston rods of the oil cylinder is four, and each piston rod is used for driving one swing arm. And flexible clamping jaws D1 arranged on the swing arms clamp and grind the workpiece E1 from the upper, lower, left and right directions.

In the clamping process, floating is synchronously performed, and the base (namely, the floating connecting frame C4) of the rotating shaft center (the pin shaft D7) of the swing arm D3 floats in two directions: in the axial direction, the floating connecting frame C4 floats between the two first steel balls C2 and the two second steel balls C3; radially, the floating connection frame C4 floats on the four rubber spacers C5. In addition, the four flexible clamping jaws D1 are made of polyurethane, have elasticity, and are elastically deformed or flexibly clamped during the process of clamping and grinding the workpiece E1. Through floating connection and flexible clamping, the influence of the chuck on the center of the workpiece in the clamping process is effectively avoided, and the positioning of the center is ensured not to be interfered or hindered.

After clamping, the floating connection is synchronized during the grinding process. In addition, the piston B1 continuously pushes the flexible clamping jaw D1 to perform clamping action under the pressure of pressure air or hydraulic oil, and a gap caused by thermal deformation is compensated.

Example 2 layout Structure of four-jaw Floating chuck

Within the 360-degree circumference range, four groups of piston rods B2, swing arms D3, flexible clamping jaws D1, adjusting screw rods D5, pin columns D6, pin shafts D7, screws C1, rubber spacer bushes C5 and other parts are uniformly distributed, the flexible connecting frame C4 is annular and is connected to the cylinder body through a plurality of screws C1 distributed on the same circumference, and more accurately, the screws C1 penetrate through corresponding through holes (located in the radial outer side area of the flexible connecting frame) on the flexible connecting frame and are screwed on the cylinder body of the oil cylinder or other fixed parts. In addition, two first steel balls C2 and two second steel balls C3 are arranged, wherein the two first steel balls C2 are respectively arranged between a flexible connection frame C4 and two screws C1 which are symmetrically arranged at two sides of the center (in the same diameter direction) and used for fastening the flexible connection frame, a gasket (or called backing plate) is arranged between screw heads of the two screws C1 and the flexible connection frame, a concave pit (shallow groove) used for arranging the first steel balls C2 is arranged on the surface of the gasket facing the flexible connection frame, and the screw C2 presses/fastens the flexible connection frame on a cylinder body or other fixed parts through the gasket and the first steel balls, so that the first steel balls are used for supporting between the flexible connection frame and the gasket.

The second steel ball C3 is arranged between the flexible connecting frame and the cylinder body (the main body part of the cylinder body and the cylinder cover jointly form the cylinder body), is positioned in the radially inner side area of the flexible connecting frame relative to the first steel ball C2, and can be matched with two pits (shallow grooves) for arranging the second steel ball C3 in the radially inner side area of the flexible connecting frame, so that the radially inner side area of the flexible connecting frame is supported on the cylinder body (the cylinder cover) through the second steel ball C3. Two second steel balls C3 are located in the same diameter direction and are adjacent to the diameter direction of the first steel ball C2 in the circumferential direction, so that floating of the flexible connecting frame is facilitated, and meanwhile, a certain distance (angle) is staggered in the circumferential direction, so that space is effectively utilized, and mutual interference of related parts is avoided.

The screw C1 is sleeved with a rubber spacer C5, the rubber spacer C5 is positioned between the screw C1 and a through hole of the flexible connecting frame for penetrating through the screw C1, and flexible connection between the screw C1 and the through hole of the flexible connecting frame is formed to allow the flexible connecting frame to float in the corresponding direction.

The transmission output end (for the other end of transmission output end, also be the jack catch link) of swing arm passes through adjusting screw D5 and connects the jack catch seat of flexible jack catch, and flexible jack catch (or the main part of flexible jack catch) fixed mounting is on the jack catch seat, and its link with the jack catch seat inserts in the jack catch seat to fix through holding screw (or called jackscrew) D2 of rotation on the jack catch seat lateral wall.

The swing arm connecting side of the adjusting screw rod D5 is screwed on the swing arm, a threaded through hole for screwing the adjusting screw rod can be formed in the swing arm, the end part of the swing arm connecting side of the adjusting screw rod extends out of the other side of the corresponding screw hole, and the end part is screwed with the positioning nut D4. After the position of the adjusting screw rod is adjusted, the positioning nut D4 is screwed, so that the adjusting screw rod can be firmly fixed.

The main body of the flexible claw is made of flexible materials, and the surface (relative to the surface) of the flexible claw, which is contacted with the workpiece, is preferably a plane surface so as to adapt to flexible clamping of the workpiece.

Since the swing arm D3, the flexible claw D1, the adjusting screw D5 and other parts need to occupy a part of space when swinging for 90 degrees, in order to avoid interference or interference among different parts/mechanisms, the screw C1, the first steel ball C2 and the rubber spacer C5 are arranged on an angle of 45 degrees away from the screw C1, the first steel ball C2 and the rubber spacer C5. Similarly, in order to avoid interference, the oil passages and the interfaces of the screw A12 and the rotary joints A5 and A8 are separated by an angle of 15 degrees.

The rotary joints A5 and A8 are respectively used for oil inlet and outlet of oil cavities on two sides of the oil cylinder, the rotary joints A5 and A8 are fixedly installed on the outer side of the cylinder body, the inner hole is communicated with the corresponding oil cavity in the cylinder body, and the two rotary joints A8 can be fastened together through a screw A12.

Since the radial space of the four-jaw floating chuck is limited, the length of the center E2 is also limited (too long reduces the rigidity of the supporting and positioning), and therefore the axial space of the four-jaw floating chuck is limited. The staggered arrangement is necessary and efficient in a confined space to accommodate mechanisms for numerous purposes such as floating connections, flexible clamping, hollow cylinders, swivel joints, four-bar pistons, swing guides, etc.

The four-jaw chuck (or called four-jaw floating chuck) is applied to an automatic production line, is respectively arranged on a headstock and a tailstock of a corresponding grinding machine, can be matched with tips on the headstock and the tailstock for use, realizes workpiece centering through the tips, and clamps a workpiece (a grinding workpiece E1) through the four-jaw chuck to rotate together. When changing the work piece, through adjusting screw D5 position on swing arm D3, can be fast to grinding work piece E1 diameter size change, and carry out the adjustment of centre gripping scope, can quick adjustment, satisfy the functional requirement that centre gripping scope was changed to anchor clamps.

The four-jaw floating chuck is characterized in that a crank block mechanism (or called swing guide rod mechanism) is composed of piston rods, swing arms and the like of the four-jaw floating chuck, the crank block mechanism is four groups in total, the shapes of the swing arms are arranged into bending shapes according to the turning requirements, quick and large-angle swinging can be realized, and the four-jaw floating chuck can be turned to leave a feeding and discharging area after a workpiece is loosened.

Example 3: matched hydraulic control system

Including oil pump F1, relief pressure valve F2, manometer F3, solenoid directional valve F4, liquid accuse check valve F5 and hydro-cylinder F6 for realize the pressure oil feed and the oil of each oil pocket of hydro-cylinder, its hydraulic control principle: the clamping and loosening actions of the four-jaw floating chuck are realized by switching the electromagnetic directional valve F4, the clamping force of the four-jaw floating chuck is realized by adjusting the pressure reducing valve F2 and observing the pressure gauge F3, and the pressure reducing valve F2 is controlled/adjusted according to pressure data acquired by the pressure gauge F3 so as to realize the required pressure. In the grinding process, if the faults of sudden power failure or insufficient pressure caused by damage of the oil pump F1 occur, the hydraulic control one-way valve F5 can lock the oil cylinder F6 to stop moving, so that the swing arm D3 is prevented from opening due to centrifugal force caused by high-speed rotation, and potential safety hazards are eliminated.

Example 4: four-jaw floating chuck working with mechanical arm

The working mode that the four-jaw floating chuck is matched with the mechanical arm to feed and discharge is as follows: along with the continuous improvement of production efficiency in modern machining industry, more and more customers demand double-drive cylindrical grinding machines, and the requirement is on full-automatic production line, and automatic unloading of cooperation manipulator, and need a cylindrical grinding machine to grind whole excircle position of work piece after once dress card. Therefore, functional requirements for the four-jaw floating chuck are met, the driving clamps are not mounted at the two ends of the grinding workpiece E1, the two ends of the grinding workpiece E1 are directly clamped by the four-jaw floating chuck G2 to be driven, the clamping part cannot be scratched, and the grinding machine is provided with a matched manipulator G4 for feeding and discharging. During loading and unloading, the four-jaw floating chuck G2 is in a loosening position, cannot interfere with the manipulator G4, and does not need to do complicated actions for avoiding the chuck in the loading and unloading interval.

Example 5: four-piston hollow rotary cylinder (four-rod piston cylinder) and four-jaw floating chuck

The existing standard oil cylinder only has one piston and one piston rod, and four standard oil cylinders are required to drive four piston rods to move, so that the same speed and synchronism of the four standard oil cylinders cannot be guaranteed. And four piston rods are arranged on the piston of the four-rod piston oil cylinder, extend out of one end of the cylinder body, can drive four jaw mechanisms simultaneously, and simultaneously omits a synchronous mechanism and a speed regulating mechanism among the piston rods.

Meanwhile, the cylinder body of the standard oil cylinder is a closed cylinder body, the cylinder body A3 of the four-rod piston oil cylinder is composed of an oil cylinder end cover A1 and a main body part (the rest parts) of the oil cylinder body, a hollow structure is formed, the cross section of the hollow structure is in a circular ring shape, an axial through hole is defined in the inner side face of the cylinder body, the chuck is installed on the main shaft, the tip penetrates through the middle of the oil cylinder A3, the requirement that the tip E2 on a headstock and a tailstock of an external grinding machine is centered on a grinding workpiece E1 is met, and the main shaft drives the chuck to further drive the workpiece to rotate.

In view of the process, in order to ensure that the four piston rods B2 run smoothly, four through holes on the oil cylinder end cover A1 and the piston B1 are simultaneously machined in the preparation process, so that the position degree of the through holes relative to the center of a part is ensured.

Example 6: flexible clamping mechanism

Four flexible jack catchs D1 clamp grinding work piece E1 from four directions, and the material of jack catchs (main part) is polyurethane, HAs elasticity, and hardness (Shore 50 ~ 80 HA) is less than work piece (HRC 40 ~ 60), can not cause the fish tail. In the double-V-shaped block chuck, the three-cam chuck and the like in the prior art, as the clamping jaws are metal hard jaws and contact parts with the workpiece are in a point shape, the clamping jaws slide with the workpiece in the clamping process to cause scratches.

After the clamping jaw clamps the workpiece, the contact part is locally deformed into a circular arc shape close to the workpiece, so that the contact area is large, the workpiece is easy to hold and clamp, and meanwhile, the clamping jaw and the workpiece are not easy to slide relatively due to friction force generated by pressure.

The swing bases of the four flexible clamping jaws D1 are all floating connecting frames C4, and are linked with each other in the clamping process, so that the grinding workpiece E1 can be better self-adaptive and clamped.

The headstock and tailstock of the grinding machine are provided with centers, a processed workpiece is centered by the centers at two ends, and the run-out and dimensional tolerance of the surface of the excircle can reach the processing requirements (0.04 mm) of the working procedure before grinding. The four-jaw chuck is clamped in a floating mode, meanwhile, the polyurethane jaws are elastically deformed, and the four jaws clamp the workpiece. During grinding, sufficient clamping force is continuously maintained by the hydraulic oil. The chuck is provided with a hydraulic control one-way valve to realize hydraulic locking, so that the clamp fault is prevented when the machine tool is powered off suddenly.

When the manipulator automatically feeds and discharges materials, the clamping claw can be driven synchronously by the oil cylinder to be away from a workpiece quickly, so that the manipulator can conveniently feed and discharge materials, and interference and collision accidents are avoided; when the manipulator leaves, can also accomplish the clamping action fast, reduced the action of manual handling clamp from this, improved machining efficiency.

When the workpiece is replaced, if the diameter of the outer circle of the workpiece is changed, the clamping range (from phi 10 to phi 50) of the clamping jaw can be correspondingly adjusted by the bolt, so that the adjustment of the clamp is quickly realized, and the machining efficiency is improved.

Four swing arms are adopted to clamp the workpiece, so that clamping jaws are easy to adjust, and the surface of the workpiece cannot be damaged.

The crank-slider mechanism is adopted for transmission, and the clamping jaws enable the workpiece to be tightly pressed towards the center in the clamping process, so that the pushing is more stable.

Example 7: floating connecting mechanism

During the clamping process, floating connection is performed synchronously, and the base (floating connection frame C4) at the center of the rotating shaft of the swing arm D3 can float in two directions. In the axial direction, the floating connecting frame C4 floats between the two first steel balls C2 and the two second steel balls C3; radially, the floating connection C4 floats on the four rubber spacers C5.

Example 8: swivel joint

Relative to the fixed joint of a standard oil cylinder, the oil cylinder adopts rotary joints A5 and A8, the rotary joints A5 and A8 are annular and are sleeved outside the cylinder body and are in sliding fit with the circumferential surface of the cylinder body to allow the cylinder body to rotate relative to the rotary joints, therefore, when the headstock and the tailstock main shafts rotate, an oil pipe can not twist, an annular opening is formed in the inner side of each rotary joint and is axially aligned with an oil cavity through hole (an oil inlet and outlet hole) in the side wall of the cylinder body, therefore, in the rotation process of the oil cylinder, the corresponding opening of each rotary joint can be communicated with the corresponding oil cavity through hole all the time, and an outer end interface of each rotary joint adopts a conventional form and is used for connecting a corresponding oil conveying pipeline.

Based on the excircle of an oil cylinder body A3, a rotary joint A5 and a rotary joint A8 are supported by two bearings A6 to do rotary motion, two ends of each rotary joint are sealed by two sealing rings A4, for each rotary joint, two bearings A6 are respectively arranged on two axial sides of the inner peripheral surface of each rotary joint, annular stepped structures (or called annular gaps) for mounting bearings can be arranged on two sides of the inner peripheral surface of each rotary joint in sliding fit with the excircle of the cylinder body, the inner peripheral surface of each rotary joint between the bearings on the two sides is in sliding fit with the excircle of the cylinder body, an annular opening for being connected with an oil cavity of the cylinder body on each rotary joint is arranged on the inner peripheral surface in sliding fit with the cylinder body, sealing rings can be arranged on the inner peripheral surfaces of the rotary joints on the two axial sides of the annular opening, corresponding sealing is realized, and other sealing modes can also be adopted. The fixing of the outer ring and the inner ring of the bearing on the rotary joint and the outer circle of the cylinder body respectively can be realized according to the prior art.

Sealing members (e.g., seal rings), fastening members (e.g., various screws for fastening/fixing connection), connection members, and instrumentation/sensors and valves for oil passages, etc. may be provided as desired.

The four rods, four claws and the like in the product name do not limit the number of the piston rods and the claws, and because the four piston rods and the four claws can give consideration to the use effect, the structural complexity and other factors in the prior art background, the invention uses the better number in the practice for the corresponding product name.

Considering that the working mechanism and action of the cylinder are the same as or similar to those of the oil cylinder, the oil cylinder can be replaced by the cylinder, or the oil cylinder referred to in the specification comprises a generally-called oil cylinder using oil/liquid as a pressure medium and a cylinder using gas as a pressure medium, and correspondingly, an oil path and the like are replaced by an air path, or the air path is included.

The technical means disclosed by the invention can be combined arbitrarily to form a plurality of different technical schemes except for special description and the further limitation that one technical means is another technical means.

Claims (10)

1. The four-rod piston oil cylinder is characterized in that an annular cylindrical cylinder body is arranged, an annular piston is arranged in the cylinder body, and a plurality of piston rods are arranged on one side or two sides of the annular piston.

2. A four-bar piston cylinder as defined in claim 1, wherein the piston rods located on the same side are equally spaced on the same circumference.

3. A four-bar piston cylinder according to claim 1 or 2, wherein the piston rod is provided on only one side of the piston.

4. A four bar piston cylinder as defined in claim 3, wherein said number of piston rods is four.

5. The four-claw floating chuck is provided with an oil cylinder and claws, and is characterized in that the oil cylinder adopts a four-rod piston oil cylinder as in any one of claims 1 to 4, the claws are fixedly arranged at the outer ends of respective swing arms, swing arm shafts are arranged at the inner ends of the swing arms, the swing arm shafts are arranged on a floating connecting frame, long grooves are further formed in the swing arms, pin columns are arranged at the outer ends of piston rods, the pin columns are inserted into the long grooves of the corresponding swing arms and are in sliding fit with the corresponding long grooves, and the floating connecting frame is annular and is in floating connection with the front side of a cylinder body.

6. The four-jaw float chuck according to claim 5, wherein said four jaws are provided, and wherein said cylinder has 4 piston rods for driving the respective jaws.

7. The four-jaw float chuck according to claim 5, wherein said swing arm is bent, said elongated slot is provided at an inner section of the swing arm, and a swing/tilt range of the swing arm is 90 ° within a stroke range of the piston rod.

8. The four-jaw floating chuck according to claim 5, wherein the floating connection frame has a plurality of through holes for passing the floating frame screws, the floating frame screws pass through the corresponding through holes and are screwed to the front end of the cylinder body, a gasket is disposed between the screw head and the floating frame, wherein first steel balls are disposed between the two gaskets and the front side of the floating connection frame, the two first steel balls are located in the same diameter direction, two second steel balls are disposed between the radial inner side of the floating connection frame and the front end of the cylinder body, the two second steel balls are located in the same diameter direction, the floating frame screws are sleeved with elastic spacers, and the elastic spacers are located between the floating frame screws and the through holes of the floating connection frame through which the floating frame screws pass.

9. The four-jaw floating chuck according to any one of claims 5 to 8, wherein the jaws comprise jaw seats and jaw bodies mounted on the jaw seats, the outer ends of the adjusting screws are connected to the outer sides of the jaw seats, the inner ends of the adjusting screws are screwed to the outer ends of the corresponding swing arms and exposed from the other sides of the corresponding screw holes on the swing arms, and the exposed parts are screwed with positioning nuts.

10. A numerical control double-drive cylindrical grinding machine is characterized in that chucks are mounted on main shafts of a headstock and a tailstock respectively, and the chucks adopt the four-jaw floating chuck as claimed in any one of claims 5 to 9.

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