31results about How to "Control preload" patented technology

The invention relates to a method for controlling the pre-tightening force of a bolt based on axial force and elongation. The method comprises the steps that when the bolt is tightened for the first time, the acoustic time difference of the bolt in the free state and the tightened state is measured through ultrasonic waves, the elongation of the bolt is calculated based on the acoustic time difference, and the pre-tightening force of the bolt is obtained according to the elongation so that the pre-tightening force of the bolt can be accurately controlled; for an in-service bolt, based on the linear relation between the propagation time of ultrasonic transverse waves and longitudinal waves in the bolt and the axial stress of the bolt, the residual pre-tightening force of the bolt is obtained so as to determine whether the in-service bolt needs to be re-screwed or not. The pre-tightening force of the bolt and the residual pre-tightening force of the in-service bolt during first-time fastening can be accurately measured, and the purpose of accurately controlling the pre-tightening force of the bolt is achieved.

The invention relates to a joint surface normal mechanical property experimental device, in particular to a normal stiffness and hysteresis characteristic test experimental device for a double-bolt joint surface. The normal stiffness and hysteresis characteristic test experimental device for a double-bolt joint surface comprises two T-shaped rods 1, a locating bracket 2, bolts 3 for testing, an eddy current displacement sensor 4 and an eddy current sensing bracket 5, wherein the two T-shaped rods 1 are respectively connected with the locating bracket 2 and the eddy current sensing bracket 5 by locating bolts; the eddy current displacement sensor 4 is fixed on the locating bracket 2 and is used for measuring the deformation of the joint surface; the two T-shaped rods 1 are connected by two sets of high-strength hexagon headed bolt assemblies for steel structures, which pass through the through holes of the T-shaped rods, the top of each bolt is provided with a hole, a strain gauge is installed on the inner side of each hole, and the pretightening force is measured by the strain gauges. The experimental device has the characteristics of simple structure, convenience in assemble and disassemble and easiness in repeated test, and capability of accurately collecting the relevant data of mechanical properties of the bolt joint surfaces.

The invention discloses a measuring device and method for rotor axial force of a double-screw compressor. The measuring device mainly comprises two groups of stress sensors arranged on two sides of athrust bearing at an exhaust end of the double-screw compressor, each group of stress sensor assembly comprises three standard stress sensors, stress is uniform, stable measurement and real-time monitoring can be realized, and the three standard stress sensors are fixed on a corresponding bracket and are mounted and positioned by through holes. The measuring device adopts two-way force measurementdesign, can accurately measure the direction and magnitude of axial force without interference to operation of a rotor.

The invention discloses a regulating device for a rear end cover of an automotive automatic slack adjuster. The regulating device is characterized in that an automatic slack adjuster bushing is sleeved on an output shaft of a clamping cylinder disposed on an automatic slack adjuster mounting base, the automatic slack adjuster is pressed by a pressure plate after the clamping cylinder is started, the automatic slack adjuster mounting base is horizontally adjusted by starting a horizontal movement cylinder, a hexagon hole of the rear end cover of the automatic slack adjuster is right aligned with and firmly abutted to a hexagon bushing, a servo motor is started to drive the hexagon bushing to rotate after rotation angle of the servo motor is set, the hexagon bushing drives the rear end cover of the automatic slack adjuster to rotate, tension of a spiral compression spring mounted inside the automatic slack adjuster is changed and adjusted, the horizontal movement cylinder is started to retreat to the original horizontal position after adjusting, and the clamping cylinder is then started to release the automatic slack adjuster to end the adjusting process. Through the regulating device for adjusting the rear end cover of the automatic slack adjuster, pretension of the spiral compression spring of the automatic compression spring can be controlled accurately, labor action is saved, labor intensity is reduced greatly and assembly efficiency is improved.

The invention relates to a downloading type plunger valve comprising a valve body, a plunger sealing ring, a support ring of the plunger sealing ring, a left connection tube, a right connection tube,a valve rod, a valve rod cap and a plunger, wherein a plunger chamber is arranged in the valve body and is a cylindrical hollow cavity which is longitudinally arranged, the plunger is arranged in theplunger chamber and is provided with a flow passage hole in a direction vertical to the axis of the plunger, the valve body is provided with an installation hole below the plunger chamber, and the installation hole is used for installing the plunger sealing ring and the plunger in the plunger chamber; the plunger valve also comprises a valve bottom cover, wherein the valve bottom cover correspondsto the installation hole, covers the installation hole and is in mutual butt fusion with the valve body.

The invention discloses a shock absorber assembly for a motor vehicle and a method of assembling the same. The shock absorber assembly for a motor vehicle comprises an oil cylinder, a piston rod and asupporting base, the oil cylinder is provided with an adjusting column protruding outwards, the adjusting column is sleeved with a movable block, and the movable block is composed of a rotating partand a tray part; a first spring assembly is arranged between the movable block and the supporting base, a second spring assembly is arranged between the adjusting column and the supporting base, and the second spring assembly is located in the first spring assembly. The two spring assemblies are composed of springs, upper limiting sleeves, lower limiting sleeves and wrinkling pieces, and the wrinkling pieces are arranged to transmit axial force and plastically deform when the axial force exceeds a threshold value. The spring assemblies are additionally arranged to replace an existing stop buffer, and the structural layout can be simplified; the two spring assemblies are each provided with a wrinkling piece, and therefore secondary threshold value control can be achieved. The displacement of the movable block on the adjusting column can control the pre-loading force of the outer-layer spring, and then the axial force threshold value which can be borne by the springs can be adjusted.

The invention discloses a friction force controllable type linear piezoelectric actuator and a control method thereof. The friction force controllable type linear piezoelectric actuator comprises a rotating block, a contact head, a fixed block, a rotor, a laminated piezoelectric ceramic, a mass block and an elastic element; the rotor can move in a first direction; the fixed block is fixedly arranged on the rotor; one end of the laminated piezoelectric ceramic is fixedly arranged on a side wall of the fixed block, and the other end of the laminated piezoelectric ceramic is fixedly connected with the mass block; the fixed block, the laminated piezoelectric ceramic and the mass block are arranged in sequence in the first direction; the second end of the rotating block can swing around the first end; the second end of the rotating block is fixedly provided with the contact head; and the elastic element is connected with the rotating block to enable the contact head to press against the rotor.

The invention discloses an assembly tool for a miniature acceleration sensor. The assembly tool comprises a multidirectional adjusting mechanism, a pressure head, a clamp and an ejector pin. The pressure head is connected with the adjusting end of the multidirectional adjusting mechanism; the first end of the pressure head is used for cooperating with the first end of the clamp to install the acceleration sensor; the mounting direction of the clamp is parallel to the second direction; a part of the acceleration sensor is positioned and placed at the first end of the clamp; a channel for the ejector pin to move is formed in the pressure head; and the ejector pin is movably arranged in the channel, and the first end of the ejector pin is matched with the first end of the clamp to install the acceleration sensor. According to the assembly tool, the clamp can be replaced, and is suitable for the assembly of various types of sensors. Under the condition that the clamp is not replaced, inner and outer conical rings, a piezoelectric patch and a positioning ring can be assembled, and the assembling efficiency and the product consistency are ensured; and the axial assembly size between the inner conical ring and the outer conical ring can be accurately controlled through a vertical fine adjustment platform, and therefore the pre-tightening force of the piezoelectric patch is effectively controlled.

The invention discloses an oil pressure type shock absorption and isolation support and a using method thereof. An upper plate trough is formed above a lower plate trough, grooves are formed in the lower portion of the upper plate trough and the upper portion of the lower plate trough, and embedded steel bars are arranged at the upper portion of the upper plate trough and the lower portion of thelower plate trough; a steel pad body is cuboid and is arranged on the upper surface of a damping layer, the damping layer is arranged in the groove in the upper portion of the lower plate trough, andthe upper portion of the steel pad body extends into the groove in the upper plate trough and makes contact with the bottom face of the groove; And baffles are arranged on the side faces of the steelpad body in the groove of the upper plate trough, an oil hydraulic cylinder used for shock absorption is arranged between each baffle and the inner wall of the groove of the upper plate trough, each baffle is connected with the upper plate trough through a position adjusting mechanism, and the position adjusting mechanisms can enable the baffles to make contact with the side faces of the steel padbody or enable preset distances to be reserved between the baffles and the side faces of the steel pad body. The hysteretic characteristic of the support can be controlled, the natural vibration period of the structure is prolonged, and the anti-seismic property of the structure is improved; and the support can be used as a fixed, one-way or two-way support.

The invention discloses an automatic detection device for an anti-slip coefficient, and relates to the technical field of anti-slip coefficient detection devices. The device comprises a work control table top; a hardware assembly is fixed to the upper surface of the work control table top, the output end of the work control table top is in signal connection with a pressure sensor, and a connecting pair is in sliding fit with the work control table top. The pressure sensor is in threaded running fit with the connecting pair, and the connecting pair comprises a connecting pair sliding table and a sliding coefficient plate; and the sliding coefficient plate is in sliding fit with the connecting pair sliding table. After the anti-slip coefficient connecting pair is installed on the device, software controls the motor to operate, the output torque is increased through the RV speed reducer, and the torque output requirement is met. And when the pressure sensor on the high-strength bolt reaches a preset value, the motor is controlled to stop, and the high-strength bolts of different specifications provide different output torques.

The invention relates to a fastener pre-tightening force control device. The fastener pre-tightening force control device comprises a gear reducer, wherein the gear reducer comprises an output end, the output end comprises a connecting head and a magnetic column, the magnetic column comprises an N pole and an S pole, the N pole is arranged at one end of the magnetic column, the S pole is arrangedat the other end of the magnetic column, and a sensor for detecting the rotation angle of the magnetic column is further arranged on a box body. The fastener pre-tightening force control device has the advantages that the rotation angle of the output end is identified through the magnetic column arranged on the output end, due to the fact that the rotation angle of a fastener during tightening isin a proportional relation with the sum of the bolt elongation and the loosening amount of a tightened part, and the fact that the deformation elongation of the fastener in the elastic area is in direct proportion to the rotation angle of the fastener, the pre-tightening force of the fastener can be accurately controlled by controlling the rotation angle of the fastener, the pre-tightening force dispersion degree of the fastener can be reduced, the pre-tightening force of the fastener reaches 70%-80% of the yield limit, the utilization rate of a material is improved, the fixing quality of thefastener is also improved, and the effects of being safe and reliable are achieved.

The invention provides a house cylindrical pouring formwork and a construction method and belongs to the technical field of house building. The formwork comprises a formwork body and a steel band, the steel band comprises two semicircular steel rings which are hinged to each other, a connecting block is arranged at the outer side of the free end of one of the two semicircular steel rings, the connecting block is provided with a threaded hole, and a fixed bolt is in threaded connection with the threaded hole; a protruding block is arranged at the outer side of the free end of the other steel ring, the protruding block is provided with a mounting hole, a nut is arranged in the mounting hole, the nut is in interference fit with the mounting hole, cover plates are arranged at the two ends of the protruding block, and the cover plates are detachably connected with the protruding block. By means of the house cylindrical pouring formwork and the construction method, the steel band can be pre-tightened rapidly, and construction efficiency is improved; formwork burst is effectively prevented, and potential safety hazards are decreased.

The invention discloses a pressure medium spring. The pressure medium spring comprises a pressure medium spring inner ring, a pressure medium spring outer ring, a pressure medium spring annular piston, a first pressure cavity, a second pressure cavity and an anti-rotation connecting piece. The first pressure cavity is formed in the other end of the pressure medium spring annular piston, and a pressure medium in the first pressure cavity can push the pressure medium spring annular piston to slide between the pressure medium spring inner ring and the pressure medium spring outer ring. The second pressure cavity is formed in the outer side of the pressure medium spring annular piston, and a pressure medium in the second pressure cavity can push the pressure medium spring annular piston to slide between the pressure medium spring inner ring and the pressure medium spring outer ring. The invention further discloses a transmission nut using the pressure medium spring. According to the pressure medium spring, the pre-tightening force of a nut in a nut lead screw pair can be controlled through the pressure in the first pressure cavity and the pressure in the second pressure cavity, the lead screw precision is improved, and the service life is prolonged.