Abstract: A lubricating oil received in a portion of a lower end side in a cylinder body is reliably supplied to a rod member and a sealing member to reliably lubricate a sliding part between the sealing member and the rod member by use of a pressure change of compressed gas in a gas spring with the rod member disposed in a posture of protruding it upward from a rod-side end wall of the cylinder body. In the lubricating structure of a gas spring, a pair of check valves preventing a back flow of a lubricating oil from the lubricating oil outlet side to the lubricating oil inlet side are provided in series in a lubricating oil passage connecting the lubricating oil inlet and the lubricating oil outlet, and the lubricating oil is introduced from the lubricating oil inlet into the lubricating oil passage and lubricating oil is discharged from the lubricating oil outlet by use of a pressure change of the compressed gas to supply it to the rod member.

Abstract: The magnetic fixing device comprises a clamping plate having a fixing surface to which a clamping object is fixed and plural magnetic force generation mechanisms. The magnetic force generation mechanisms each comprise a magnetic material member facing the fixing surface, plural permanent magnets arranged around the outer periphery of the magnetic material member, a first Alnico magnet placed on the back of the magnetic material member, and a first coil for switching the polarity of the first Alnico magnet, and can be switched between the absorption state in which the clamping object is adsorbed and the non-absorption state in which the clamping object is not adsorbed. An operation state indication mechanism capable of presenting an indicator indicating that the plural magnetic force generation mechanisms are in the absorption state or in the non-absorption state is provided on the fixing surface or outer periphery of the clamping plate.

Abstract: A fixing structure of a spindle balancer for a machine tool in which a spindle balancer can be attached easily to a machine tool at an appropriate position in an appropriate posture while being supported stably and surely by the machine tool, safety is enhanced when the spindle balancer is attached to the machine tool by lessening the attaching load, set-up including replenishment of the cylinder body with compression gas and regulation of gas pressure is facilitated, and the attachment time and set-up time of the spindle balancer can be shortened.

Abstract: Intended is to provide a method for positioning a work (15), which is adapted for a knock hole of a small diameter and which can absorb a pitch error between a main positioning hole (16) and an auxiliary positioning hole (17) of the work (15). An insert shaft (21) of main positioning means 820) is inserted into the main positioning hole (16). Auxiliary positioning means (30) includes a base lower block (36) having a parallel slide holding surface (36e), a sliding flange (34b) having a sliding surface (34c), and an insert shaft (31) disposed above the sliding flange (34b). The sliding flange (34b) of the auxiliary positioning means (30) is guided and moved by the slide holding surface (36e), and is inserted, while absorbing the pitch error, into the auxiliary positioning hole (17), thereby to position the work (15).

Abstract: Provided is a machine tool spindle balancer that stably pulls and biases the spindle unit upward and thus reduces the load of the lift means for moving the spindle unit vertically, is easily applicable to existing machine tools, highly durable, downsizable, and has a simple structure advantageous in production cost. A spindle balancer 30 comprises a gas spring 31 having a cylinder body 32, a rod 33, and a compressed gas. The gas spring 31 is provided above the spindle unit 10. The bottom end of the rod 33 is coupled to the spindle unit 10 so that the spindle unit is pulled and biased upward by the biasing force of the gas spring 31 that is applied on the rod 33, whereby the biasing force of the gas spring 31 serves to reduce the load of the lift mechanism 20.

Abstract: The injection molding machine has a fixed platen and a movable platen for fixing a pair of molds; a pair of clamp plates mounted to the fixed platen and the movable platen, respectively, and having a fixation surface for mold fixation, respectively; and magnetic force generation mechanisms for generating a magnetic force for fixing the molds to the fixation surfaces, and, an air-gap formation means for automatically forming air-gaps between the fixation surfaces and the molds in association with the movement start of the movable platen while the magnetic force generation mechanisms are inactivated for detaching the molds from the fixation surfaces is provided at least in one of the clamp plates.

Abstract: In the positioning and clamping device (3), a positioning mechanism (13) has an annular tapered surface (40) that is formed on the outer periphery of a cylindrical shaft (10b) for positioning a pallet (1) in the horizontal direction, and has a decreasing diameter toward the axial tip of the cylindrical shaft (10b), and an annular engaging mechanism (41), which is formed on the inner periphery side portion of an annular engagement member (11), to engage with the annular tapered surface (40), and is elastically deformed in the radial direction, as a result of engagement with the annular tapered surface(40), and the engaging mechanism (41) has a tapered ring portion (50), which makes a face contact with the annular tapered surface (40), and multiple ribs (51) extending outward, radially, from the tapered ring portion (50).

Abstract: The coupling apparatus for bringing a pallet 3 (a movable article) near to a base side support 2 from above, positioning it in the horizontal X, Y directions and in the vertical Z direction, and clamping it in a releasable manner comprises a pair of first engaging protrusions 12 and a pair of second engaging protrusions 13 formed on the top surface of the support 2 for positing in the X direction and in the Y direction, respectively; a pair of first movable article side engaging protrusions 32 each abutting the pair of first engaging protrusions 12 on one side and a pair of second movable article side engaging protrusions 33 each abutting the pair of second engaging protrusions 12 on one side; a Z direction positioning mechanism 8 for positioning the pallet 3 relative to the support 2 in the Z direction; and a clamping mechanism 7 for clamping the pallet 3 on the support 2.

Abstract: A main shaft includes a plurality of elastic engagement pieces arrayed along an outer perimeter of an attachment hole. During and after assembly, the elastic engagement pieces elastically abut at least an outer surface of a tapered shank in a tool holder and deform slightly in a radial direction. The elastic engagement pieces provide uniform engagement force between the main shaft and the tool holder over a broad surface area. An elastic flange provides additional elastic engagement and easy separation from the main shaft. Together, the elastic engagement pieces and elastic flange reliably engage and securely attach the main shaft to the tool holder while aiding disengagement.

Abstract: A gas spring (7) comprises a cylinder main body (20); a rod member (21) slidable to cylinder main body; a gas filled chamber (23) filled with compressed gas and urging the rod member in a first direction; a rod inserting hole (32) inserting the rod member (21); an annular collar (24) slidable on the rod member at a position apart from the rod inserting hole in the second direction opposite to the first direction; an annular groove (24a) on the annular collar which is open toward the second direction; and a lock ring (26) engaging with an annular ring mounting groove (25) on the rod member (21). In assembling, the lock ring (26) is moved in the first direction together with the rod member, to thus engage with the annular groove (24a) on the annular collar, so that the annular collar for stopping the rod member and the lock ring is stopped by an end wall of the cylinder main body.

Abstract: A workpiece support has a simplified structure and can operate with improved dependability and reliability. The workpiece support has a rod, a sleeve body externally fitted on the rod and elastically deformable so as to shrink in diameter, a case member supporting the sleeve body, and an external peripheral hydraulic chamber formed on the external periphery of the sleeve body. A hydraulic cylinder is provided for moving the rod in the axial direction and oil passage are provided for connecting the hydraulic operating chamber of the hydraulic cylinder with the external peripheral hydraulic chamber when the piston member of the hydraulic cylinder has moved up to or to the vicinity of the stroke end thereof.

Abstract: A workpiece support provides enhanced reliability of operation and enhanced durability. The workpiece support comprises a rod, a sleeve body, a case member, a scraper, an external peripheral hydraulic chamber, and oil passages, and is further provided with an air passage formed between the rod and the internal peripheral surface of the sleeve body, and connected to the small gap between the rod and the scraper, and an air input port for supplying compressed air to the air passage; wherein compressed air is supplied from the air input port to the air passage and expelled from the small gap between the rod and the scraper when the rod is retracted.

Abstract: A clamp device is disclosed which maintains a stable clamped state, even if an object to be fixed, being a work pallet or die, is clamped in a repeated fashion, and which is compact in size and yet capable of clamping the object to be fixed with a large clamping force.

Abstract: A gas spring has a cylinder body, a rod member internally slidably fitted in the cylinder body, and a gas chamber which is formed inside the cylinder body and filled with compressed gas. The seal members for sealing between the cylinder body and the rod member are disposed at both sides of the gas chamber, while ring members for partitioning the gas chamber are disposed at the end portions of the gas chamber close to the seal members, and accordingly, annular grease chambers for grease between the seal member and the ring member are formed, and it is possible to prevent grease shortage by the grease in the grease chambers.

Abstract: A clamping device 2 is provided with a hydraulic cylinder 7 for biasing a collet member 5 upward via a collet supporting member 6 and driving a pull rod 4 downward. A piston member 30 has a greater pressure receiving area than the collet supporting member 6 in the circular hydraulic chamber 31 of the hydraulic cylinder 7. Therefore, the hydraulic cylinder 7 can drive the pull rod 4 downward while the collet member 5 is biased upward. Meanwhile, the collet 5a of the collet member 5 is resiliently deformed in a diametrically expanding manner to engage in the vertical bore 1b of a workpiece 1 while slightly moving downward, ensuring a secure locking of the workpiece 1 to a workpiece receiving surface 3a.

Abstract: The present invention presents a work pallet positioning and fixing device capable of positioning in both horizontal and vertical directions through elastic deformation of an annular engaging portion, wherein the engaging portion can elastically deform along the entire periphery and even locally in a circumferential direction thereof.

Abstract: A work pallet that is arranged to be simple in construction capable of machining five faces of a work by rotating it around the axis of rotation. A work pallet (4) comprises a base body (5) detachably fixed to the table (3) of a machine-tool (1), a pallet main body (6) fixed on the top face of this base body (5), and a work setting face forming body (7), provided on this pallet main body (6) in a way to turn around the rotational axis (20) and having a work setting face (21a) for fixing a work (2), and the pallet main body (6) is provided with a clamping mechanism (31) for releasably fixing the work setting face forming body (7), and a rotational driving mechanism (32) for rotationally driving the work setting face forming body (7) around the rotational axis (20).

Abstract: A gas spring comprising a cylinder body filled with compressed gas and an upright rod passing through a rod side end wall member of the cylinder body. By supporting a main shaft unit with the gas spring, the load on a vertical displacement mechanism is reduced. A pair of upper and lower ring-shaped seal members, which seal between the rod end wall member and the rod, are provided inside the rod wall member. Ring-shaped oil filling chambers are formed in between the ring-shaped seal members and between the rod end wall member and the rod. An oil filling mechanism fills the oil filling chambers with lubrication oil.

Abstract: The abutment of the rod to the work piece is accomplished in a stable manner by providing an air passage in the inside of the work support for supplying pressurized air for detecting the abutment between the rod and the work piece. Work support is equipped with case, rod, sleeve that elastically deforms to reduce its diameter, hydraulic cylinder for driving rod in an advancing direction, spring for elastically energizing rod in advancing direction, detection nozzle for ejecting pressurized air, air passage connected to detection nozzle, sensor for detecting abutment between the tip of rod and work piece based on air pressure, and a control unit. Work piece is supported by the tip of rod abutting work piece while ejecting pressurized air from detection nozzle, and locks rod by elastically deforming sleeve to reduce its diameter after detecting the abutment of rod by a pressure sensor and control unit.

Abstract: A machine tool main spindle balancer wherein the annular sealing members of a gas spring that supports the main spindle unit to reduce the load of an elevating mechanism are easily replaceable. A gas spring of a machine tool main spindle balancer comprises a cylinder body, which is filled with a compressed gas, a rod that extends downward from the inside of cylinder body, a head-side end wall member of cylinder body having a filling valve, a sleeve member forming a circumferential wall around a rod insertion hole mounted hermetically and detachably on a rod-side end wall member, and annular sealing members and mounted on said sleeve member, so that annular sealing members can be replaced easily by discharging the compressed gas, and removing only sleeve member while holding rod on head-side end wall member.