2932results about "Chucks" patented technology

The utility model relates to the technical field of return wheel type hexagonal lathes, in particular to an adjustable clamp for a return wheel type hexagonal lathe. Comprising a chuck body and an inner supporting device, a rotating bolt, a small bevel gear, a large bevel gear, a screw groove and a clamping jaw are installed on the outer side of the chuck body, the inner supporting device is installed in the middle of the chuck body, and a servo motor, a reciprocating lead screw, an inner supporting sliding block, an inner supporting push rod and an inner supporting clamping block are installed in the inner supporting device; a square groove hole and a guide sliding groove are formed in the side, close to the inner supporting clamping block, of the inner supporting device. A servo motor drives a reciprocating screw rod to rotate, an inner supporting sliding block slides along the reciprocating screw rod, at the moment, the inner supporting sliding block pushes an inner supporting push rod to turn over along a rotating shaft pin and pushes an inner supporting clamping block to make contact with the inner wall of a circular pipe to support the circular pipe, and after fixing, a rotating bolt is rotated to drive a clamping jaw to clamp the outer wall of the circular pipe; in this way, the round pipe can be effectively prevented from being pressed, deformed and damaged in the using process, and the production efficiency and effect are guaranteed.

The invention belongs to the technical field of clamping, and provides a self-adaptive shape follow-up centering clamp and an automatic clamping method. The self-adaptive shape follow-up centering clamp comprises an end cover, an outer circular ring, a floating shape follow-up positioning cylinder, a driving clamping cylinder, an inner circular ring, a hanging ring, a rib plate and a PLC control system. The automatic clamping method can replace a traditional process ring clamping method, self-adaptive shape follow-up positioning and clamping of the barrel workpiece are achieved, the process ring turning procedure is omitted, and material consumption is reduced. After the outer circular ring, the cylindrical roller bearing and the axis of the lathe spindle in the self-adaptive shape follow-up centering clamp are mounted consistently, it can be guaranteed that the middle barrel section coincides with the axis of the lathe spindle. Shape-following positioning of a blank barrel workpiece is achieved through the floating shape-following positioning cylinder, the barrel workpiece is clamped through the driving clamping cylinder, and it is guaranteed that stress is uniform while the axis of the barrel workpiece does not deviate. The device is achieved based on a PLC control system, the clamping force is quantitatively controlled through feedback adjustment of the oil pressure gauge and the proportional valve, and clamping deformation is reduced.

The invention discloses a power chuck machining device capable of compensating clamping and automatically pushing materials, and particularly relates to the field of chuck machining, the power chuck machining device comprises a chuck base, a plurality of clamping jaws are arranged on the chuck base, and the multiple clamping jaws clamp and fix a thin floating disc by synchronously and radially moving along the surface of the chuck base; a supporting piece is arranged on the chuck base and makes contact with the bottom of the thin floating disc. The supporting piece is arranged to support the thin floating disc, the supporting force of the thin floating disc is effectively increased, the possibility that the thin floating disc deforms due to external force in the turning process is reduced, higher rigidity is provided, vibration and bending of the thin floating disc can be effectively restrained, the stability in the machining process is improved, and the machining precision is ensured; and by arranging the adsorption mechanism, the action of force can be more uniformly distributed, vibration is reduced, the turning quality is improved, a smoother surface is obtained, and the size precision and the surface quality in the turning process are further ensured.

A transmission mechanism (200) and an electric chuck. The transmission mechanism (200) comprises a lead screw (201), a lead screw nut (202), and a pull rod connecting shaft (204). The lead screw (201) is provided with a power connection end connected to a power mechanism (100), and the lead screw (201) rotates under the drive of the power mechanism (100). The lead screw nut (202) is located in front of the power connection end. The lead screw nut (202) is sleeved on the outer circumference of the lead screw (201), the lead screw nut (202) is matched with the lead screw (201) by means of threads, and the lead screw nut (202) is driven by the rotation of the lead screw (201) to move back and forth along the axial direction. The pull rod connecting shaft (204) is located in front of the lead screw nut (202), the pull rod connecting shaft (204) is connected to the lead screw nut (202), the pull rod connecting shaft (204) is driven to move axially by an axial movement of the lead screw nut (202), and the pull rod connecting shaft (204) is configured to drive a clamping jaw transmission assembly (300) to move axially. The transmission mechanism (200) can convert a rotation output of the power mechanism (100) such as a motor (101) into a linear movement and output same to the clamping jaw transmission assembly (300) and a clamping jaw (400), so as to implement a clamping action or an opening action of the clamping jaw (400).

Quick-change hole saw mandrel (10) for a hole saw (18); includes drive shank (14) extending along a central axis (C); and mounting end (16) detachable connected to mounting aperture (26) of hole saw (18) and including drive pin (30) for engagement with drive pin aperture (28) of the hole saw (18). The mandrel (10) includes a gripping arrangement (32) insertable through the mounting aperture (26) for gripping the hole saw base (20). In a normally expanded configuration the gripping arrangement (32) grips the base (20). The gripping arrangement is selectively movable to a contracted configuration in which it can be inserted into or removed from the mounting aperture (26). A pilot bit lock selector (44) for selecting between an unlocked mode permitting quick removal and quick insertion of the pilot bit (12) and a locked mode in which the pilot bit (12) is locked against removal.

A tool exchange device in which a tool unit is detachably attached, the tool exchange device includes: a device body in which a motor accommodation chamber for accommodating an electric motor is formed; a cylindrical member provided in the device body and to which a plurality of balls engaged with an engagement ring provided in the tool unit are attached; a cam member attached inside the cylindrical member and rotated and driven by the electric motor arranged in the motor accommodation chamber; and a ball drive surface provided on the cam member and having a lock surface for engaging the ball with the engagement ring and a release surface for releasing the ball from the engagement ring.

2. Machining system, comprising at least a driveable holder receptacle (10) and a holder (12) provided for receiving a machining tool, the holder having a holder shaft (14) and being interchangeably lockable in the holder receptacle (10) by means of a locking device (16), wherein the locking device (16) is movable from a release position to a locking position and vice versa by means of an actuating device (18) during a locking or release operation, in which the holder (12) is guided into the holder receptacle (10) in a manner that allows it to be inserted into and removed from it, or is held in its inserted position in the holder receptacle (10) and is drawn in with a predefinable clamping force, wherein the holder (12) has at least one clamping cam (96) arranged on the holder shaft (14) which is engaged or disengaged for a locking or release operation.in addition to the system with an assignable clamping surface of the fixing device (16), characterized in that the holder receptacle (10) has a spring-elastic compensating device (24) which enables, at least in the fixing position, a tolerance compensation between holder receptacle (10) and received holder (12).

The invention discloses an integrated machining device suitable for a large marine propeller, which comprises a machining adjusting assembly, the machining adjusting assembly is composed of an X-axis moving mechanism, a Y-axis moving mechanism and a Z-axis moving mechanism, one side of the Z-axis moving mechanism is fixedly provided with a rotating mechanism, one end of the rotating mechanism is fixedly connected with a cutting assembly, and the other end of the rotating mechanism is fixedly connected with a cutter; according to the large marine propeller integrated machining device with the automatic machining function and the self-adaptive clamping function, through the integrated multi-axis linkage machining adjusting assembly and the three-dimensional scanner, automatic path planning can be conducted, and automatic operation is achieved; therefore, the dependence on advanced technicians is greatly reduced, the machining efficiency and the product consistency are remarkably improved, and meanwhile, through the collaborative design of the rotatable three-jaw chuck and the center supporting mechanism, simultaneous reliable supporting from the interior and the exterior of the workpiece can be automatically achieved during clamping.

The invention relates to an automatic clamping transmission chuck for an axle numerical control lathe. The automatic clamping transmission chuck comprises a power supply control box, a stop key, a hexagon socket screw I, a travel switch, a copper pin, a spring and a center body, the power supply control box is fixed on one side in the center body; the stop key is arranged on one side of the rear end face of the center body in the radial direction. The inside hexagonal bolt I is mounted on the stop key; axial cylindrical grooves are respectively formed in the upper side and the lower side of the front end of the tip body; the copper pins are respectively and correspondingly connected in the cylindrical grooves in a sliding manner; the spring is axially arranged between the inner end of the copper pin and the cylindrical groove; the travel switches are fixed to the two sides of the interior of the center body, and the signal input ends of the travel switches on the two sides are correspondingly connected with the inner sides of the two copper pins respectively. One-time clamping machining of the axle can be completed, time and labor are saved, the machining efficiency is improved, and the machining quality of the axle can be improved. The problems that traditional clamping wastes time and labor, the coaxiality of secondary clamping is poor, and automatic clamping cannot be achieved are effectively solved.

The utility model relates to the technical field of numerical control machinery, in particular to a workpiece chuck for numerical control machining of aluminum alloy. The device comprises a connecting column, a clamping platform is fixed to the top end of the connecting column, limiting blocks are evenly distributed and fixed to the top end of the clamping platform, sliding rods are slidably connected into the limiting blocks, connecting blocks are fixed to the ends, away from each other, of the top ends of the five sliding rods, and sliding columns are fixed to the ends, close to each other, of the top ends of the five sliding rods. Clamping jaws are fixed to the ends, close to each other, of the top ends of the five connecting blocks, and a clamping mechanism is arranged at the top end of the sliding rod. According to the workpiece chuck for numerical control machining of the aluminum alloy, the five clamping jaws are driven by the clamping mechanism to clamp a cylindrical workpiece in the direction away from or close to one another, so that the stability and practicability of the device in the workpiece machining process are improved, and the working efficiency of the device is greatly improved; the clamping range of the device is increased according to different sizes of cylindrical workpieces.

A power tool system including a power tool base having a main body, an electric including an output, and a tool-side attachment mechanism coupled to the main body, the tool-side attachment mechanism having a tool-side locking lug and a tool-side slot adjacent the tool side locking lug. An accessory is configured to be selectively coupled to the power tool base and includes an accessory-side attachment mechanism having an accessory-side locking lug and an accessory-side slot, the accessory-side locking lug selectively engagable with the tool side slot and the accessory-side slot selectively engagable with the tool-side locking lug, a gear arrangement configured to be operably coupled to the output of the electric motor to receive torque from the electric motor, and a tool holder configured to be driven by the gear arrangement. The accessory-side attachment mechanism selectively engages the tool-side attachment mechanism to axially couple the accessory to the power tool base.

A spindle for a polygonal hollow-shaft taper is proposed which permits optimal use of the interior of the spindle for receiving a clamping system and an optional cylinder structure.

The invention relates to the technical field of machining equipment, and discloses machining equipment for producing automobile parts, which comprises a chuck, the chuck comprises a chuck body, a plurality of clamping jaws and a plurality of cleaning parts, the plurality of cleaning parts are in one-to-one correspondence with the plurality of clamping jaws, and each cleaning part comprises a first telescopic rod, a connecting plate and a first air blowing pipe, the first telescopic rod is connected to the inner wall of the back face of the chuck body and located in the chuck body, the first telescopic rod is perpendicular to the chuck body, and the connecting plate is connected to the first telescopic rod so that the connecting plate can reciprocate in the perpendicular direction of the chuck body along with stretching and shortening of the first telescopic rod. A plurality of openings are formed in the first air blowing pipe, the first air blowing pipe is connected with an air blowing pump, and air is blown out from the openings of the first air blowing pipe along with movement of the connecting plate to blow away chippings on the clamping jaws. According to the equipment, chippings on the clamping jaws can be cleaned, and the possibility of errors of parts is reduced.

The utility model discloses an adjustable floating chuck suitable for a heavy horizontal lathe, which relates to the technical field of heavy horizontal lathes and comprises a chuck body. The bottom of the main shaft is in threaded connection with the bottom of the chuck main body; the outer side of the floating assembly is in sliding connection with the inner side of the chuck main body; the top end of the pull rod is fixedly connected with the bottom of the floating assembly; the outer side of the first clamping assembly is rotationally connected with the outer side of the floating assembly; and the outer side of the second clamping assembly is rotationally connected with the two sides of the floating assembly. According to the device, materials are clamped by arranging the first clamping assembly and the second clamping assembly, the materials are prevented from inclining, the production efficiency of the materials is improved, and the clamping precision of the first clamping assembly and the second clamping assembly is enhanced by arranging the floating assembly and adjusting the first clamping assembly and the second clamping assembly.

The invention is suitable for the technical field of part machining, and provides a hardware part machining drilling machine which comprises a base and a three-jaw chuck arranged on the base, and a control frame is further installed on the base in a sliding mode. The drilling mechanism comprises a lifting frame, a supporting box, a control box, a spraying box, a driving motor and a drill bit, the lifting frame and the control frame are in sliding connection through a lifting assembly, and a rotating speed type flow control assembly and a pressure type flow control assembly are further arranged in the containing cavity and the spraying box correspondingly; through the arrangement of the drilling mechanism, the problems that when an existing drilling machine is used, cutting fluid is sprayed at will and cannot be accurately sprayed to a drilling position, so that a drilling structure is prone to overheating, meanwhile, the spraying amount of the cutting fluid cannot be adjusted according to the hardness of a to-be-machined part, and the drilling efficiency is improved are solved. The phenomenon of waste or insufficiency of the cutting fluid is easy to occur, and certain limitation exists.

The utility model discloses a manual type self-centering three-jaw chuck device, which relates to the field of machining equipment, and comprises a chuck main body, a rotating disk and a pressing plate piece, the outer end face of the chuck main body is provided with a rotating disk mounting groove, and the outer end face of the rotating disk is uniformly provided with three arc-shaped grooves in a surrounding manner; three clamping jaws corresponding to the three arc-shaped grooves are movably arranged on the pressing plate piece; the rotating disc is installed in the rotating disc installation groove, a manual adjusting screw rod is arranged on the annular face of the rotating disc, the pressing plate piece is connected to the outer end face of the chuck body, the rotating disc is buckled in the rotating disc installation groove, pin shafts inserted into the arc-shaped grooves are arranged on the three clamping jaws respectively, and the rotating disc is rotated through the manual adjusting screw rod. The rotating disc synchronously controls the three clamping jaws to clamp the workpiece on the pressing plate piece or loosen the workpiece through the three arc-shaped grooves.

The utility model discloses a four-jaw chuck with a dust-proof mechanism, which comprises a fixed seat, a mounting plate is rotatably mounted on the surface of the fixed seat, a four-jaw chuck main body is arranged on the surface of the mounting plate, the four-jaw chuck with the dust-proof mechanism further comprises a shielding cover, and the inner wall of the shielding cover is attached to the surface of the four-jaw chuck main body. According to the scheme, the electric push rod contracts to drive the shielding cover and the extension cover to be attached to the clamping jaws on the surface of the four-jaw chuck body and cover the sliding grooves containing the clamping jaws to move, and when the clamping jaws move, the spring arranged in the first connecting base enables the extension cover to synchronously move along with the clamping jaws and to be continuously attached to the clamping jaws; according to the four-jaw chuck provided by the invention, the clamping jaws move to cover the sliding grooves again after the clamping jaws move, so that dust generated in the machining process can be prevented from entering the chuck through the sliding grooves by covering the sliding grooves, the driving assembly is ensured not to be influenced by the dust, and the four-jaw chuck can be normally used.

The invention relates to the technical field of machining, and discloses a ring part inner hole machining fixing clamp which comprises a fixing ring, a driving assembly used for driving is installed in the middle of the fixing ring, a clamping mechanism used for clamping a part is installed between the driving assembly and the fixing ring, and the driving assembly comprises a rotating ring. The rotating ring is rotationally connected to the inner side of the fixed ring, the outer side of the rotating ring is fixedly connected with a pull rod, and the other end of the pull rod is rotationally connected with a clamping force adjusting assembly. The clamping force adjusting assembly drives linkage of the rotating ring and the rotating rod, the clamping plates can automatically get close to workpieces, tight attaching clamping of the workpieces of different sizes is achieved through deformation of the clamping plates and elastic force provided by the elastic pieces, and therefore the clamping efficiency and adaptability are greatly improved, meanwhile, the extending length of an extending plate is finely adjusted through an adjusting bolt, and the clamping efficiency is improved. The positions of the clamping plates can be accurately adjusted, and clamping errors are eliminated.

The invention belongs to the technical field of inner star wheel clamps, and particularly relates to an inner star wheel quick-change high-precision clamp which comprises a clamping shell, a clamping component is arranged in the clamping shell, the clamping component comprises a quick-change clamping block, and the quick-change clamping block clamps an inner star wheel. According to the quick-change high-precision clamp for the inner star wheel, the clamping component and the driving component are arranged, a chute is in inclined sliding fit with an inclined rod, and a pushing taper sleeve drives the conical surface of a roller on an inserting rod, so that the single axial movement of a driving hydraulic cylinder is creatively changed into the single axial movement of the driving hydraulic cylinder; according to the three-jaw chuck, the three clamping jaws are synchronously decomposed and converted into the composite motion of radial shrinkage and axial compression of the three clamping jaws, and the structure enables the clamp to actively and reliably restrain the axial degree of freedom of a workpiece while clamping the outer circle of the workpiece, so that the defect that the axial constraint of a traditional three-jaw chuck is weak is overcome. The method has the following direct effects: firstly, a machine tool is allowed to process by adopting larger cutting depth and feed rate, so that the processing efficiency is obviously improved, and the service life of a cutter is prolonged;

The invention relates to the technical field of automobile part manufacturing, discloses an adjustable multi-angle trimming and deburring device for automobile part machining, and provides a scheme that a trimming machine tool is matched with a multi-angle trimming mechanism to solve the problems that in the prior art, the clearing efficiency of flashes and burrs at a center hole and a heat dissipation groove of a brake disc is low, and positioning is not accurate. According to the device, a four-jaw chuck is driven by a driving motor to rotate a brake disc, a ball screw, a movable block, a connecting rod and other assemblies are utilized, four sets of trimming cutters synchronously trim a center hole, the inner side, the outer side and the bottom face corners of a heat dissipation groove correspondingly, a buffering inserting rod and a spring are combined to absorb impact, and precise operation of the cutters is guaranteed through the design of a deflection rotating shaft, a magnet and the like. According to the scheme, burrs at multiple positions are cleaned at a time, clamping errors are eliminated, energy consumption and cutter abrasion are reduced, the structure is compact, the device is suitable for automatic trimming of brake discs of different sizes, and the machining efficiency and precision are remarkably improved.

The invention relates to the technical field of machine tool clamps, in particular to a chuck clamp with an adjustable clamping angle and an angle adjusting method. Comprising a chuck body and movable clamping jaws, the multiple movable clamping jaws which are annularly and evenly distributed are arranged on the chuck body, a first step and a second step are arranged on the end face of each movable clamping jaw, the multiple movable clamping jaws can be close to or away from the center of the chuck body from the end of the chuck body, and an adjustable clamping plate is movably connected to the positions, close to the center of the chuck body, of the movable clamping jaws. The clamping angle of the adjustable clamping plate is adjusted through an angle adjusting system, the angle adjusting system comprises an adjusting bolt, a controller and a human-computer interface, the adjusting bolt is in threaded connection with the adjustable clamping plate and the movable clamping jaw, and the adjusting bolt is driven by a micro motor. According to the invention, a workpiece with a tapered excircle can be effectively clamped, the inclination angle of the chuck fixture can be accurately controlled, the clamping is simpler and more convenient, the clamping time is shortened, and the workpiece processing quality is ensured.

The invention relates to a tool holder for the, in particular force-fit, mounting of a tool, in particular a rotary tool, and to a kit, in particular for such a tool holder. The tool holder comprises a receiving body which has a rotary axis, a rear interface for receiving the tool holder in a work spindle of a machine tool, a front receiving section for the force-fit retention of the tool, in particular the rotary tool, a coolant bore arranged along the rotary axis between the interface and the receiving section, by means of which coolant can be guided along the rotary axis from the interface to the receiving section and which has a first area with a second area adjoining it in the direction of the rotary axis towards the receiving section, wherein a diameter of the first area is larger than a diameter of the second area, and a coolant pipe arranged in the first area of ​​the coolant bore which has a diameter larger. Towards the receiving section, a cavity is formed in the receiving body or in the first area with the increased diameter between the coolant pipe and the smaller diameter second area of ​​the coolant bore. To improve the coolant flow and thus the cooling of a tool, the tool holder is designed with a bridging element in the cavity between the coolant pipe and an interface-side end of the smaller diameter, second area. This bridging element is designed to allow coolant flow and seal the coolant flow against the cavity.

The invention relates to a rotary chuck linking mechanism which comprises a machine body, a rotary table is rotationally arranged on the machine body, a clamping mechanism is installed on the rotary table, the clamping mechanism comprises a chuck base, a chuck and a plurality of clamping jaws, the chuck base is installed on the rotary table, the chuck is installed on the chuck base, and the clamping jaws are arranged on the chuck base. The multiple clamping jaws are evenly arranged in the circumferential direction of the chuck in a sliding mode and synchronously slide in the direction close to or away from the center of the chuck. The chuck replacement device has the effect of facilitating chuck replacement.

The invention provides a rotary force transmission device and a machine tool, the rotary force transmission device comprises a power connecting part, a machine tool spindle fixing part, a first clutch mechanism, a screw rod, a screw rod nut and a pull rod connecting shaft, the screw rod nut is matched with the screw rod, the screw rod nut can translate front and back when the screw rod rotates, and the pull rod connecting shaft is mounted at one end of the screw rod nut; the driving connecting part is located at the input end of the lead screw, the machine tool spindle fixing part is close to the output end of the lead screw, part of the first clutch mechanism is connected with the power connecting part, and part of the first clutch mechanism is connected with the lead screw, so that the power connecting part is in transmission connection with the lead screw or is separated from the transmission connection with the lead screw. The rotary force transmission device provided by the invention can be directly sleeved in the machine tool main shaft as a related part, and the structure has better reliability.

Disclosed herein is a power tool comprising a motor, a drive shaft connected to the motor, a front end defining a cavity comprising a tool side end and a free end, and a coupling mechanism for releasably connecting a removable tool head to the drive shaft. The coupling mechanism comprising two sleeves, a first and a second biasing element and at least one ball that together either put the coupling mechanism in an open position ready to receive the removable tool head or into a closed position upon manual dislocation of the inner sleeve during insertion of another tool head, so that the at least one ball can glide into at least a partial engagement with a recess on the removable tool head and is locked there via the inner projection of the outer sleeve, which outer sleeve is held in position by the first biasing element.

An element changer includes a plurality of operation pin members (4) inserted in a housing (3). Each of the operation pin members (4) has a wedge surface (12c). When the operation pin members (4) are pushed into the housing (3), each wedge surface (12c) is disengaged from an engaging portion (10a) provided at a leading end portion of a tubular wall portion (10) of a tool plate (2) or of a connection plate (1). This allows a tool (5) functioning as a second element to be detached from a robot arm (8) functioning as a first element.

The invention relates to the technical field of machining, in particular to a parallel double-spindle double-station intelligent turning center which comprises a bottom plate, vertical plates extending upwards are fixedly connected to the left side and the right side of the bottom plate, first supporting seats are fixedly connected to the upper side of the bottom plate in a bilateral symmetry mode, and second supporting seats extending upwards are fixedly connected to the rear portion of the upper side of the bottom plate. The machining mechanism and the feeding and discharging mechanism are used in cooperation, the machining efficiency of workpieces can be effectively improved in a double-spindle and double-station synchronous machining mode, meanwhile, by means of an oblique feeding mode, the machining efficiency of the workpieces can be effectively improved, and the machining efficiency of the workpieces can be effectively improved. According to the tool turret assembly, the machining influence of cooling liquid and chippings on workpieces is effectively reduced, the follow-up cleaning time is saved, the tool can be rapidly assembled and disassembled, the assembling and disassembling efficiency of the tool turret assembly is effectively improved, installation is stable, and time and labor are saved in use.

The invention relates to the technical field of bearing machining, in particular to bearing ring automatic machining equipment which comprises a supporting plate, a driving device is fixedly mounted at the upper end of the supporting plate, and a turning head for machining a bearing ring is fixedly mounted at the driving end of the driving device. A rotating screw head is twisted to rotate and move in a connecting barrel, the moving rotating screw head drives a rotating ring to move, the rotating ring drives a telescopic support to move, the telescopic support drives a rotating frame to rotate and drives a first rotating head and a clamping jaw to rotate, and the rotating clamping jaw enables a clamping face to incline; therefore, when the bearing ring with the inclined outer side face or the inclined inner side face is clamped, the clamping jaw can have more contact area with the bearing ring, so that the clamping stability is guaranteed, and the clamping face of the clamping jaw can be driven to adjust different angles by rotating the screw head to clamp the bearing rings with different inclined faces.

Provided is a tool bracket capable of tilting a spindle body even when a moment load acting on the spindle body is relatively small. A tool bracket includes: a housing including a cylinder chamber extending along a cylinder axis; a piston urged by compressible fluid toward distal end to reciprocate in the cylinder chamber and having an action portion disposed at distal end; and a tilting body having a tilt axis and disposed in the cylinder chamber in a tiltable manner with respect to the cylinder axis, and includes a centering portion disposed at basal end to abut the action portion, the centering portion presses the piston with the cylinder axis as an action line when the tilt axis is tilted from the cylinder axis.